New Labour allowed the "successful techniques of opposition to spill over too often into government", according to Tony Blair's polling guru Philip Gould.

But the mistake, confined to Mr Blair's first term as prime minister, was only "a moment on our journey. It didn't work, and we learnt and we changed."

The comments from Mr Gould, one of the architects of New Labour, come in an article for BBC News Online and as he addressed a Hansard Society conference about "the permanent campaign".

Philip Gould is strategic polling adviser to Prime Minister Tony Blair

The prime minister's strategic polling adviser rejects the notion that a US-style permanent campaign - something New Labour has been accused of importing - now exists in the UK.

Mr Gould suggests a "new politics of conviction, honesty, and dialogue" is emerging.

'Too much' campaigning

Critics who believe there is a permanent campaign make the mistake of downplaying the significance of the party's struggle to electability, says Mr Gould.

That effort included "a long line of revisionism and modernisation ... sometimes strong, often weak, until Tony Blair and Gordon Brown finally reinvented progressive politics in Britain in the mid-1990s".

Labour's history of defeat pre-Blair meant that "professional campaigning and opinion polling became vitally important".

Mr Gould concedes, however, that "for a while we allowed the successful techniques of opposition to spill over too often into government.

"We did campaign too much in the early years of power. But this was a moment on our journey. It didn't work, and we learnt and we changed."

New Labour is now leading the way in a new approach to politics, says Mr Gould: "The permanent campaign is old politics, it has had its day."

"A new politics of convictions, honesty, participation and dialogue is replacing it."

He calls on the media to respond to the new "political candour" of the government, with its increased accessibility and diminished emphasis on polls and press coverage, in a fair manner.

"We must all of us acknowledge our shared responsibilities to change politics for the better."