Budget Day is a curious thing. It’s pure theatre – a parliamentary set-piece that is treated with reverence by media and politicos alike. Today’s was no exception, especially as it was almost certainly Gordon Brown’s last before he moves next door.

The odd thing about budgets – the UK government variety at least – is that the initial reviews are often wildly wrong. Blame the theatre – it’s as if only a third of Shakespeare’s Hamlet was actually performed on first night, with the rest of the play emerging in instalments over the following months. The famous example is Nigel Lawson’s 1988 budget, which cut the top rate of income tax to 40p. Lawson was applauded as a visionary, reforming chancellor. But within months the budget had fuelled an inflationary boom that led to bust. (Remember double mortgage tax relief?) Two years later, mortgage rates hit 15.4 percent and Lawson’s reputation was battered.

Today’s budget cut the basic rate of tax by 2p to 20p – a move guaranteed to hit the headlines. But I wasn’t the only one not to notice that Brown had also abolished the 10p tax rate, which will hit people on lower incomes. A strange move by a Labour chancellor. And one that confirms that budgets are about tricking as well as treating.

Almost everyone watching today’s budget will have judged Gordon Brown as prime minister-in-waiting as well as chancellor. The headlines in recent weeks have been about the Conservatives opinion poll lead over Labour – and how a Brown premiership would actually widen the Tory lead. How Brown must be cursing his fate as Westminster’s eternal Prince of Wales, as the Guardian’s Jonathan Freedland characterised him in his article today.

Is it unfair to blame Brown for Labour’s imploding poll ratings? In many ways, yes. The electorate are tired of new Labour and the tiresome quarrel between its twin leaders. But much of the malaise is down to Iraq – Blair’s latest and most disastrous war. But this does not mean that Labour will lose the next election, which will surely not take place until 2010. Three years is a long time in politics.

But shouldn’t a change of leader refresh Labour’s appeal, as John Major’s arrival at number 10 revived Tory fortunes? Not necessarily. Major was almost unknown in 1990, despite his 16 month meteoric rise as foreign secretary, chancellor and PM. Swapping Thatcher for Major felt like a change of government to many. By contrast, Brown is all too well known. So far, the public do not warm to him. They blame him as much as Tony Blair for the pathetic quarrel between the Downing Street neighbours. (David Cameron’s best line in his budget response was to mock the annual Blair-Brown conversation.) But don’t assume we know exactly what a Gordon Brown premiership might be like. It’s not impossible that Brown in power might assume a confidence and ease that we’ve not seen before. We shall see.

The BBC reports that Conservative leader David Cameron has fired his security spokesman Patrick Mercer for making "unacceptable" remarks about ethnic minorities in the armed forces.

I suspect Cameron made the right decision. But am I the only person who had never heard of Patrick Mercer before today? It suggests that he’d never said anything of interest before!