First, all the usual health warnings: we shouldn’t get too excited about individual polls; there’s still a lot of time before the next general election; the electoral system is skewed towards Labour, etc., etc.

But it’s still worth noting the two polls in today’s papers that put Labour’s lead over the Tories at only 1 percentage point. Specifically, there’s the Survation poll in the Mail on Sunday that has Labour on 35 per cent and the Conservatives on 34. And then there’s the YouGov poll for the Sunday Times (£) that has those numbers at 37 and 36.

It’s the context of these polls that really matters. The day before the Budget, Labour’s lead in YouGov polling stood at 4 percentage points. The day before that it was 8 percentage points. Has Osborne given his party a boost?

Back in my Coffee House days, I noted the improbability of a post-Budget bounce. At my insistence, the brilliant Anthony Wells also did some work on this. We both came to the same broad conclusion: that Budgets either didn’t really change attitudes towards the governing party, or they had a negative effect.

The Wells-style graph I’ve produced below, comparing the two YouGov polls before a Budget with the two YouGov polls after*, puts this in pictorial form. Even when Gordon Brown announced a 2p cut to the basic rate of income tax in 2007**, Labour’s poll rating still fell:

Budget poll leads

In fact, the poll bounce after this latest Budget – if that’s what it is – is really only one of three in the last decade. The others were 2006 and Osborne’s first Budget, in 2010.

Are the pension reforms responsible? Is it the cut to alcohol duty? As Wells points out in a recent post, it’s actually the general impression that counts more. For instance, according to YouGov polling, 47 per cent of people think that this year’s Budget was fair, against 26 per cent who think it was unfair. That’s the best result since that 2010 Budget.

And it’s the even more general impression that should give Tories heart. Whether this Budget bounce continues, or whether it recedes, it remains true: Labour’s poll lead has diminished markedly over the past year.

* A quick note about the numbers behind the graph. Before the last election, YouGov conducted their polls roughly every week. After the election, they became daily. This means that the numbers for Osborne’s Budgets are closer to the actual Budget days than for Darling’s Budgets. I’ve avoided using any results produced on the Budget day itself.

** Yes, I know that he did this by terminating the 10p rate – but that didn’t really percolate through to the papers until the following year.