Martin Kettle explained the authorship of the budget clearly in The Guardian:
‘Lord Mandelson was sitting in the gallery almost in Alistair Darling’s line of sight as he delivered his budget speech today. When the chancellor sat down, Mandelson was quick to go first on camera on the BBC to give his spin on the speech. These connections are important. For while this was Darling’s day, and Darling’s budget, it was also Mandelson’s day and Mandelson’s budget. The business secretary’s fingerprints were all over it.
‘Inside the government it has been Mandelson who has led the fight against Gordon Brown’s instinct to use the budget as a way of pitting "Labour investment" against "Tory cuts". Mandelson’s view is that Labour has to be honest about the deficit, now reduced slightly to what is still an eye-watering £167bn next year, and that Labour must be willing to talk about cuts – albeit cuts when the time is right – when they do not put the slow and fragile recovery at hazard. That was the approach Darling adopted in the budget today, as he did in the pre-budget report at the end of 2009, and which looks set to be part of a developing story of departmental cuts that will be announced from Whitehall this afternoon… As ever, one must guard against exaggeration and oversimplification, but the 2010 budget, which may be Labour’s last for a long time, was a very Mandelsonian speech. It was not the kind of budget that Gordon Brown would have given – full of spending on public services aimed at propitiating the public sector unions… Alistair Darling may have delivered the budget but Lord Mandelson is its co-owner.’
Gordon Brown declined to endorse Alistair Darling’s deeper cuts than Thatcher remarks. He was right to do so.
The right wing Blairites have already done serious damage to Labour in the run-up to the election. This started with Hewitt and Hoon’s attempted ‘leadership coup’ – their standing was of course shown by the fact that they are now being investigated over the scandal of whether they attempted to sell influence for money. But the biggest damage may have been the Mandelson budget. There are only a few weeks to try to reverse the damage done by this budget and to try to ensure it is not fatal.