The central questions in the forthcoming election campaign remain the same, and so do the answers.

On the question of which party is best able to meet the challenges facing Britain, which party has the experience and the judgement and strength in depth to secure the recovery, which party has a policy agenda for the future that is rooted in values of fairness, which party will protect frontline services without making dogmatic and unfair cuts, then a good case can be made that the answer to all of those questions is Labour. Labour has to keep making that case with verve, vigour, guts and gusto.

The Tories scored a media hit with their national insurance non-rise, and it may in part have played through to the polls. But far from enhancing their economic and political credibility, over the course of a campaign, it can be shown to have further damaged it.

Easy politics does not make for sound economics. Making promises without having the first clue how to fund them – today’s papers are littered with them – is simply evidence that they have given up on long-term credibility in the pursuit of what they hope will be short-term political popularity.

So far from removing from Labour’s claim to be the best party to secure the recovery, as the Tories claim, the NICs move underlines it. Labour long term v Tory short term. Consistency v opportunism. Leadership v weakness. Sums that add up v sums that don’t.

All the promises made today, if followed through, would lead to fresh economic calamity in a Tory tomorrow. We know the media like a lot of what the Tories are saying and doing because most of them back ‘time for a change’ either because they are bored with Labourafter three terms or because they are actively supporting the Tories. But over the remaining weeks of this campaign, there is a very good chance the public will think about some of these issues more deeply, see through the Tory strategy of making promises they cannot keep, and understand too that the same David Cameron who spoke of standing up to vested interests a short time ago, of facing up to tough choices and doing the right thing for the long-term, is now doing the exact opposite.

He and his colleagues will say anything, even if they know they will have to end up doing something very differently, and even if they know that their sums don’t add up.

Labour has to stay focussed on those big questions and the big challenges facing the country. This was always going to be a tough campaign, for all of the parties. But at least GB has a record to point to, of taking difficult decisions and seeing them through. It part explains why we have a recovery at all. When the going looked like getting a bit tough for Cameron, politically, he chose the soft economic option and the easy road. He gave up on the deficit as his number one issue and reverted to where his party always wants him – promising tax cuts he won’t be able to fulfil if he is to meet his other pledges. It has won him a short-term headline battle. But in the weeks ahead, it may not seem quite as clever ashe and George Osborne seem to think.

— Buy The Blair Years online and raise cash for Labour http;//www.alastaircampbell.org/bookshop.php.