There is a £34 billion black hole in the Tories' spending plans, Alistair Darling claimed today as Labour stepped up its campaign ahead of this year's general election.
The Chancellor said the Conservatives had accounted for only about a quarter of the funding needed to deliver their pre-election pledges.
He made the accusation as Labour released a 150-page dossier analysing recent Conservative pledges.
Mr Darling said its findings were based on the Tories' own figures and Treasury-produced costings. The shortfall could only mean tax rises or deeper spending cuts, he said.
"The Tories have made over £45 billion of promises, but can barely explain how they can pay for a quarter of this," Mr Darling said.
"This leaves them with a credibility gap of £34 billion.
"These are not long-forgotten promises from another time. All have been confirmed in the last two years. Most have been repeated in the last few months.
"You can't fight an election on a nod and a wink, sometimes claiming you are committed to these promises, and when challenged claiming you are not.
"It's now for them to say when and how they'll be paid for. Or come clean and withdraw them."
Mr Darling said Tory leader David Cameron had spent the past couple of years going around the country telling people "whatever he thinks they want to hear".
The cost of Conservative promises on tax and spending now came to £45 billion, he said.
The figures were based on the Tories' own costings except where there was "clearly more recent or credible numbers available", including Treasury figures.
"What is clear is that the Conservatives have so far only set out how to raise a fraction of the money needed to pay for their plans to introduce new tax cuts, reverse current tax changes and fulfil their spending commitments," he said.
"Just to meet those promises, let alone to cut the deficit faster, they would need new tax rises and deeper cuts to public spending elsewhere."
The Chancellor said he would tomorrow be presenting legislation to Parliament enshrining the Government's commitment to halving the deficit over the next four years.
The Labour dossier claimed that Tory plans for tax cuts would cost £21 billion a year by the end of the next Parliament, while reversing planned tax rises would cost another £13.3 billion.
Another £11.1 billion would have to be found to pay for spending commitments that have been made, Labour said.
The Tories' efforts to find savings in Whitehall expenditure would yield only £6.6 billion at best, while tax rises pencilled in by shadow chancellor George Osborne would raise £5.1 billion.
The alleged £34 billion black hole that would result would be on top of any cuts required to bring down the deficit "further and faster" than Labour, as intended.
Halving the deficit just one year faster than the Treasury already planned would require another £26 billion of spending cuts or tax rises, Labour said.
Earlier Schools Secretary Ed Balls sought to turn the spotlight on education. He said Labour would increase spending on education as he set out plans to guarantee extra tuition for primary school pupils who fall behind.
"The schools budget will go up every year, year on year, this year, next year and the year after. The Conservatives are saying they would cut education this year and next," he told GMTV.
"The reason is that they have got different priorities. They want to have an inheritance tax cut which goes to millionaires, which would mean that they could not match us on education spending."
Mr Balls also appeared to confirm that a general election was some time away.
When asked whether the Conservatives had "stolen a march" on Labour with their campaign plans, he said: "I don't think so, because we are going to have months of this before the actual election comes along."
Mr Balls insisted on BBC Breakfast that engaging early with pupils with a problem was effective.
"We are saying in law we will set out a guarantee to parents: if your child falls behind, our investment will ensure your child gets that extra help."Reuse content