I have thought long and hard, having said two months ago I didn’t intend to get involved in the Labour leadership debate, about whether to publish this piece. I am also aware that there is a risk that it will have precisely the opposite of the effect I hope it has – namely to make people think twice about backing Jeremy Corbyn – as his supporters take to social media to tell each other that if Blair’s spinmeister is against him, he must be alright. I am aware too that I may be helping a right-wing press I despise more than most by enabling them to throw me into the mix of a Labour summer mayhem story; and that having in part given up frontline politics because I was fed up of family holidays being constantly interrupted by ringing telephones, I may be provoking a few calls as I head out on a bike ride up a mountain.

But just as if out on that ride I saw a car crash about to happen I would do what I could to alert the drivers to the danger, so I think I have to say something about what appears to be happening to Labour right now. Car crash, and more.

Apologies in advance for the length, but I guess I have been doing what Marilyn Monroe used to call ‘thinking in ink,’ and I hope that those yet to be caught up in so-called Corbynmania, and who feel maybe they ought to be, will read and think through with me to the end.

Now the last time I saw Jeremy Corbyn, we surprised ourselves by agreeing on something. It was the day after the general election, and we were sharing our disappointment in a makeshift tented BBC studio on Westminster’s College Green as the British people absorbed the reality that they had decided to send David Cameron back to Downing Street with a majority. And we both made the point to Five Live’s Peter Allen that it would be better for Labour to have a real debate about the Party’s future, really analyse and learn lessons from such a terrible defeat, rather than plunge straight into a leadership election that would become a personality contest taking the place of such a debate.

At that stage, Corbyn had not even considered standing, and neither of us imagined for a moment that within a few months he would be the candidate making the weather in the leadership debate, sufficient to be thought of as a possible winner. There was also plenty we disagreed upon, as you would expect when putting together a New Labour ‘control freak’ who feared the country was never going to elect Ed Miliband’s brand of soft leftism, and a 500-plus times rebel against the whip of successive Labour leaders. But the biggest disagreement related to the position he was beginning immediately to stake out, that Labour lost because we were not left wing enough. It is the argument that has been put forward by some in the Party all my political lifetime, and the ultimate beneficiaries have always been the Tories not Labour.

What I will say about that encounter, and the few others I have had with Jeremy Corbyn, is that he is likeable, sincere, a good local MP, and millions of miles away from the detestability of a George Galloway or other lesser known figures on the far left who have done so much more to damage Labour than help it.

Also, it is good that Corbyn is inspiring hitherto disenchanted young people to get involved in politics, and that he is seeking to fire them up with positive messages about change. But it is also important that those who see him as some kind of cross between Russell Brand, Nicola Sturgeon and their favourite uncle take a little bit of time to look at the recent history of the Party they are joining so they can help him to become leader, and weigh it all up in the balance.

That history is made up of all too few spells in government – albeit often making the most important changes to our national life, from the NHS to a Scottish Parliament, from the welfare state to the minimum wage – and long, long periods in Opposition. Tony Blair, whom it has become all too fashionable to despise on the left, was the first Prime Minister to deliver TWO full consecutive terms in office for Labour, let alone the three he won. And Alan Johnson did a very good job last week in reminding the Corbyn-supporting union leader Dave Ward, who had spoken of Blair as a ‘virus’, and New Labour as being too obsessed with winning, that the Blair governments did a lot more good for working people than the Cameron government Labour failed so miserably to defeat on May 7.

If you have already read Alan’s piece, you can skip the italicised bits here, but I thought this section was worth reprinting.

I can understand why the “virus” drivel should emanate from our political opponents, including those in the various far-left sects who last tried to bring their finger-jabbing intolerance into our party 35 years ago. What I’m puzzled by is why it should come from trade union leaders whose members benefited so much under the last Labour government.

Leave aside the transformation in health and education (plus additional jobs and extra pay for nurses and teachers), the 3,000 Sure Start centres, the Disability Discrimination Act, the Human Rights Act, civil partnerships, rescuing 1.2 million children from absolute poverty and 1.8 million from relative poverty, pension credit (which made the single biggest contribution to the fact that for the first time in recorded history being old is no longer associated with being poor), the Pension Protection Fund, the resuscitation of apprenticeships and the world’s first legally enforceable carbon reduction targets. Is it accurate to suggest that trade unionists fared badly in the Blair years?

Hardie’s vision of a national minimum wage wasn’t enacted by MacDonald or Attlee, Wilson or Callaghan; it was introduced by the Blair government along with the right to paid holidays (later extended by law to be in addition to bank holidays). Every single worker was given the right to be accompanied at a disciplinary or grievance hearing by a trade union official, regardless of whether the union was recognised and irrespective of whether the individual was a member. During the “virus” years, a woman’s right to paid maternity leave rose from 16 weeks to nine months. Paternity leave was introduced for the first time.

The ban on trade union representation at GCHQ was lifted along with the pernicious “check-off” legislation, which forced unions to re-recruit their members every three years. The Public Disclosures Act gave protection to whistleblowers, new rights were enacted to protect part-time and temporary workers, agency workers and those subjected to control by gangmasters. Legislation on union recognition insisted that if 50% plus one of the workforce was recruited, the union was automatically recognised. Prior to 1997 it had always been the case that an employer could sack striking workers en masse on day one of a dispute. The Blair government changed the law to prevent that happening.

Far from being a period when trade unions were betrayed, it was the most benign period in their history and, if I may gently point out to Ward, the importance of winning elections can be summed up in four words – the trade union bill.

In short: Labour governments do more good for working people than Tory governments. But first you have to win power. To many who have recently joined the Corbyn campaign, they have only ever known Blair as PM, Gordon Brown for a short time, and David Cameron, first without a majority, now with one. Labour having been so dominant during their childhood and youth, they can be forgiven for thinking there is a kind of pendulum in our politics that goes Labour – the Blair-Brown era – then Tory – the Cameron-Osborne era – and then it will go back to Labour, and step forward Jeremy with his anti-politics look and his anti-establishment talk and his ability late in his career to get people queueing round the block to hear him.

Well here is an interesting historical fact upon which to reflect. Eton College, alma mater of our current PM and current London Mayor, has produced more Prime Ministers than the Labour Party. Now my reaction to that – I suspect this too I have in common with Corbyn – is to say that it shows the extent to which our class-based establishment has long dominated Britain, its politics and society, and Labour is the party that has to change that. But it is also a reflection of what the left is up against when it comes to winning power at the highest level.

I am beginning to fear that Mr Cameron, surely the least strategic Prime Minister of our lifetime, is beginning to pass Napoleon’s test for generals by being the luckiest. He told his wife on the morning after the 2010 election that he feared they would not after all be moving into Downing Street. Five days later, helped by Nick Clegg, he was there. Five years on, he left Downing Street staff in little doubt that he thought they would be having a new boss after the election. But the fear among the non-committed, who ultimately decide elections, that a Miliband-led minority coalition propped up by the SNP would not represent stable or effective government, allied to the Tories winning the politics of the economy because of what the Guardian’s Larry Elliot today rightly called the ‘catastrophic misjudgement’ of failing to rebut the idea Labour caused the crash, was enough to get Cameron over the line.

Clegg has talked of it being ‘an accidental majority,’ in that the result reflected what the country did not want, rather than what it did. The country did not particularly want Cameron back in Number 10. But the desire not to have that Labour/SNP government was, alas, much stronger.

The views of the general – and generally not politically-obsessed – public are not insignificant in all this. The two main parties, when choosing a leader, are picking the person they intend thereafter to try to persuade the people of the UK ‘this is who should be your Prime Minister.’ And yet the Labour Party, if it elects Jeremy Corbyn as leader, is selecting someone that every piece of political intelligence, experience and analysis tells you will never be elected Prime Minister. Just as Margaret Thatcher loved it when Neil Kinnock was having to expend more energy dealing with the hard left than he did with her – all the time being attacked as a sell-out by the Corbynites of the day – so the Tories cannot believe their luck at the turn Labour’s election is taking. That too is an important factor. Our job is not to help them do theirs. They have enough advantages already.

I don’t know how many of Corbyn’s new fans are aware of Derek Hatton and Tony Mulhearn, who ran and almost ruined Liverpool (a great city hammered by the Tories and which did well under a Labour government by the way), but these were Labour people who helped keep Neil Kinnock out of Downing Street, and Margaret Thatcher in Downing Street. Back then, though the unions have often been a cause of difficulty for the Labour leadership, there was enough common sense among union leaderships and executive committees to know that the hard left route, if adopted by the Party as a whole, was a march over the end of a cliff.

But it is not just today’s wannabe Hattons and Mulhearns, but also many of today’s major unions and their general secretaries, as we have seen, who are pushing hardest for Corbyn to be Labour leader. Whatever the niceness and the current warm glow, Corbyn will be a leader of the hard left, for the hard left, and espousing both general politics and specific positions that the public just are not going to accept in many of the seats that Labour is going to have to win to get back in power.

I am not talking about safe seats like Islington North, where Corbyn has done a very good job in driving up his majority. I am talking about marginal seats whose defeated candidates contributed to the Fabian Society review of the election, who are pretty clear that Labour did not lose for being ‘not left wing enough,’ but because the leader wasn’t popular or seen as a credible PM, we weren’t trusted on the economy, we were seen as anti-business, and though we were ok at saying what we were against, we did not have the most compelling or convincing vision of what we were for, and how we would make it happen.

I campaigned in several of the seats covered in that review. It was indeed hard work trying to win people over to some of the policy arguments we were putting forward, or trying to persuade sceptics in Bury with Jamie Frith or in Darwen with Will Straw that Ed Miliband got aspiration, supported business, or would know how to stand up to Vladimir Putin or ISIS. But once you add in some of Corbyn’s fixed positions, then frankly Labour is moving from difficult conversation with the undecided voter to not being allowed over the doorstep. Some of the positions winning him the loudest applause in his packed meetings are those that will be met with the most deafening silence when campaigners get out on the doorsteps of the undecided come election time. His long career has laid a plentiful minefield for currently quiet Tory researchers and campaigners. The past, he will discover, is not another country.

The voices of those who fought and lost those marginal seats in the recent election, as well as those who fought and won, and therefore have the right to stand for election to succeed Ed Miliband, are every bit as important as the voices dominating the debate now. More so in fact, if we are serious about Labour being a party of power, rather than just a party of protest that marches, campaigns, backs strikes, calls for ministerial resignations, more money for every cause going, shouts and bawls and fingerjabs but is ultimately powerless in the face of changes the government is now making, freed from the constraints of coalition, loving the chaos that Labour’s election has unleashed.

And whilst I accept that I cannot survey the post electoral scene and say with any certainty  that a Labour Party led by Andy Burnham, Yvette Cooper or Liz Kendall will win the next election, I think I can say with absolute certainty that a Corbyn-Tom Watson led Labour Party will not. For that reason alone, I agree with Alan Johnson that what he called the madness of flirting with the idea of Corbyn as leader has to stop. That means no first preferences, no second preferences, no any preferences. It frankly means ABC, Anyone But Corbyn.

Nor should anyone imagine that once he is there, it will be easy to replace him, no matter how low we fall in the polls. On the contrary, if he fails to win, many of those who helped him get close to it will feel they can just keep on playing the politics of opposition against whoever beats him, and use their new found influence in the party to take that person out.  If Corbyn wins, no matter how inclusive and emollient he might try to be, then stand by for his supporters and backers bringing back the politics Kinnock and others fought so hard to beat. I doubt that the deselection processes will spare those MPs who nominated him to get him on the ballot paper and now say they regret it. In short, stand by for chaos, in the PLP and in the party in the country. To those of his supporters who will say this is alarmism, I say just look back and see how this story has unfolded before.

All of us who have been part of the Labour Party these last few decades know plenty of people for whom the internal politics is more important and more exciting than what politics can do for those who frankly often don’t give much of a damn even if they should. At a nomination meeting in one of Corbyn’s neighbouring seats in North London, a woman hitherto unseen at party meetings, arguing against another woman urging support for Yvette Cooper, proclaimed that Corbyn was the only choice because ‘I care more about  socialism than power.’ I am sure David Cameron says amen to that. To hear people say ‘it doesn’t matter if we win’ is to see people for whom political choice is about what makes them as individuals feel better, not what might make the country a better place. The sincerity of the belief in great causes, and the desire for change, is clear among the Corbyn crowds. But none of that change can come from Opposition.

I remain of the view that Labour would have done better to have had debate first, leadership election second, but that horse has gone. I also said at the outset that the reason I did not intend to back any candidate publicly was that if nearer a general election the Party feels we have little chance of winning, we should become a lot more ruthless about changing leader mid-term. I stand by that. I said then, almost two months ago now, ‘I am a big believer in unity but not in collective denial dressed up as unity.’

Of course unity would not be easy for Corbyn to inspire or manage, given his track record, and he would need to rely on others showing discipline he has never shown himself. But the collective denial is already in danger of beginning, among those deluding themselves that a country that decided against electing Gordon Brown, Neil Kinnock, Ed Miliband or Michael Foot is going to elect someone who at various points felt all four were frankly too right-wing. I’m sorry, but it just isn’t going to happen. I do not believe the Party would  split. I just think we would be telling the country we have have decided to open an even bigger gulf than the one that became clear on May 7, and given up on being a serious party of government.

Corbyn is indeed an OK guy, a good MP, and his stance clearly chimes with many people’s views of anti-austerity in particular. He is also successfully tapping into some people’s disappointment both at New Labour, whether on Iraq, tuition fees or simply not changing the country as much as they wanted it be changed; and also at Ed Miliband’s failure to defeat a government doing so many bad things especially to the very poor who have had to pay the price for a global economic crash caused largely by the very wealthy.

But everything I have seen both of leadership, and of Labour, tells me Corbyn’s ability to lead and hold the Party together is likely to be low; his ability to reach those parts of the country we have been losing, whether to the Tories, to UKIP or the SNP, will be even lower. This will sound like madness to those flocking to hear him speak, and doubtless be dismissed by them as just another old New Labour figure bleating on about the glory days of three wins in a row. I love their idealism just as they probably deride my pragmatism and my obsession with winning. But they bring to my mind Michael Foot’s exchange with  MP John Golding who tried to warn the then Labour leader that he was heading for a huge defeat against Margaret Thatcher, and Foot’s response was to say no, because a thousand passionate people were turning out every night to hear him speak. It brings to mind too the more recent conversations of the converted on twitter when we managed to convince ourselves that Ed Miliband was heading to Number 10.

If he wins, Corbynmania will evaporate even more quickly than Cleggmania did, once the pressures of real, difficult decisions and the day to day leadership of the main Opposition kick in. I fear that activists currently cashing in on perceived ‘betrayal’ by past Labour leaders are going to end up feeling very badly let down.

One of the worst aspects of the so-called Corbynmania is that it is obscuring the solid decent abilities of the other candidates, who are each one of them better than most of the media will acknowledge, and far better equipped for the hard graft of detailed policy-making that has a chance of actually happening, so that we can make more of the kind of change Alan Johnson wrote about. The right-wing press has a dream template for this contest,  ‘loony left’ (sic) v mediocre careerists (sic). That portrayal of Corbyn may be unfair to him (though understand the media has not even got started 0n him as actually most of our enemies want him to win because of the chaos they know will follow). But the portrayal of the other three is just as unfair to them. Of this I am certain however: if the Tories are ever to be defeated by progressive forces in the system we have (and which we cannot change unless we have power) then the hard work that needs to be done is going to have to be done on the centre left represented by those three, not through policy prescriptions of the past and a sudden love-in with someone speaking up for those prescriptions, but who knows in his heart he will not be able to make them happen.

Burnham, Cooper and Kendall need to show now that they understand they are in a fight not just to be Labour leader, but to save the Party. That is a big challenge and one of them needs to demonstrate they can step up to it by showing that they too know how to make the weather in a campaign. And anyone who wants to see another Labour government one day should do what people who want a Corbyn leadership are doing – namely sign up as registered supporters for three quid in the next few days; but then I would hope they  vote ABC. With those three, I could see possible routes both to defeat and also to victory in the country. With Corbyn, I’m afraid I can see only the route to defeat, and much, much worse. I wish it wasn’t so. But it is. And it is horrible to watch, unless you’re David Cameron, or George Osborne, as things stand his likeliest successor in Number 10.