Before I get onto politics, well done to Eddie Izzard as he finishes his incredible run around the UK. For most runners, one marathon is a big enough challenge. By the end of today, Eddie will have done 43 in 52 days, all the way raising money for Sport Relief.

I first heard of his plan when he and I appeared at a Euro elections rally for students in the Midlands. I honestly thought it was a gag, and he was going to make ultramarathon runners a new seam for material. Over dinner afterwards, I realised he was serious. Even then, the scale of the challenge he had set himself seemed so vast, it was hard to imagine that he would complete the course.

Well, barring a last day disaster, he has, for which he deserves enormous respect.

If I was in London, I would head down to Trafalgar Square to cheer him in – he reckons he will get there about half past four – but I am up in Scotland.

I did a Labour Party fundraiser for Scottish Secretary Jim Murphy last night, who is defending a 6000 majority in East Renfrewshire. Back in the days when I was a political journalist, the seat was called Eastwood, and it was one of the safest Tory seats in the country.

On election night 1997, as I record in my diaries, the moment we realised we were on course for a landslide was at TB’s count in Sedgefield, when we watched the results programme on TV, and seats were falling that we had never expected to win. This was one of them. As Jim recalled last night, he had started the campaign thinking it would get him good experience, but without leading to a radical change of lifestyle. ‘I thought you said you had no chance of winning?’ his wife said to him on election night.

Twelve years on, he is still MP, and in the Cabinet. But both of us hammered home the message that this election will be tougher than the previous three. That much is obvious from the polls.

Yet if David Cameron has not sealed the deal with the electorate in England, he is even further away from doing so in Scotland. But of course the political scene is much more complicated up here, with the SNP in power at the Scottish Parliament, and still pursuing its independence agenda.

Jim made the point that there are two ways of getting a Cameron government in Scotland – voting Tory, or voting SNP. The independence fight also becomes easier for Salmond up against a Tory government than a Labour government.

One year on from the collapse of Lehman Brothers, and the global financial crisis it provoked, it is worth remembering just how badly Scotland’s banks came out of what followed, and just how much they relied on GB’s leadership, and the UK government’s support, to ensure the relative stability that has followed. At a time when people seem so loathe to give Gordon credit for anything, his actions this time last year should not be overlooked. And nor should Salmond’s prior claims that Scotland would have been stronger had it been more like Iceland.

The signs are that he is trimming a little on what independence actually means, and what form it might take. But it remains the driving purpose of his party, and he knows a Tory government in Westminster is a step in the right direction for him. Another good reason to try to stop it from happening.