David Cameron admitted today that he had "messed up" over the Tories' commitment to a marriage tax break, but insisted it would be delivered within a Parliament.
After days of Labour claims that Conservative tax policy was in disarray, the Tory leader sought to draw a line by saying he had simply "misdescribed" his party's position.
Confusion about the policy partly overshadowed a major Tory election campaign launch on Monday, when Mr Cameron appeared to downgrade his commitment to a tax incentive for marriage.
Having previously promised that it would be introduced under a Tory government, he told an interviewer that he only "hoped" to do so.
Mr Cameron was forced to issue a statement later saying that the party was, in fact, pledged to deliver on the policy within a Parliament.
Prime Minister Gordon Brown joined Labour taunts about the matter when he and Mr Cameron squared up over the Despatch Box in the Commons yesterday.
The Tory leader said this morning: "The truth is, I give dozens of interviews every week and on Monday I messed up and there is no other way of putting it.
"I was thinking about all sorts of different things, and I misdescribed our policy. I immediately corrected that.
"But in my view there's only one thing worse than messing up, and that is messing up and not admitting to it."
He restated that the Tories would recognise marriage "properly" in the tax system within their first Parliamentary term.
"We have to be very careful about the commitment and pledges we make but that is a pledge we feel we are able to make," he told the BBC Radio 4 Today programme.
Mr Brown jibed yesterday that Mr Cameron could not give a "straight answer" on his marriage tax proposal, "whether you can say 'I do' or 'I don't' on it".
Mr Cameron admitted that the Tories were not currently pledged to abolishing income tax on savings for people on the basic rate.
That had been a 2009 "budget submission" which the Government had not taken up, he said.
Tory calls for 5,000 more prison places had been "partly done" already by Labour, Mr Cameron said.
But he insisted that the Tory promise to freeze council tax for two years still stood.
"We have a pledge to do that because we've found the money to do that, which was by cutting government advertising and government consultancy," he said.
The Tory leader said the chapter-by-chapter publication of his party's manifesto would enable him to update the country on revisions to its commitments.
"The reason for having a draft manifesto - and the next chapter will be published next week - is we will be able to set out what has changed and what the Government has done that we've suggested, which I think is important," he said.
Mr Cameron sidestepped accusations that his image had been airbrushed for a new poster campaign by the Conservatives.
A large portrait of his head and shoulders forms the centrepiece of a poster which has been put up in almost 1,000 locations across the UK.
But commentators have noted that his features appear to have been touched up.
Asked about whether they had, he laughingly said: "I certainly hope not."
He went on: "I made the decision that I wanted a strong positive start to the campaign.
"And I think having strong, positive posters... of course I'm going get ribbing from my friends and not least my family about having my picture up there."
He added: "Look, I don't produce the picture or the poster."Reuse content