Leafletgate deepens as Gordon Brown is accused of "fear and smear"

Senior Conservatives rounded on the Prime Minister, demanding he apologise for literature, sent out by MPs and government ministers, which they insist contains false claims about Tory policies.

The allegations sparked one of the most heated exchanges of Thursday night's televised debate, when David Cameron challenged Mr Brown to withdraw leaflets he insisted contained "pure and simple lies" about the Conservatives' intentions for tax credits, child trust funds, healthcare and perks for pensioners.

Some leaflets issued by Scottish Labour candidates claim the Tories plan to axe the winter fuel payment and free bus travel, despite a clear pledge to maintain both things in the Conservative manifesto.

And an election newsletter distributed by Chancellor Alistair Darling in his Edinburgh South West constituency, and by other Scottish Labour candidates, claimed the Conservatives would slash child tax credits for couples earning 16,000 or more each, an allegation vigorously denied by the Tories, whose manifesto indicates the threshold would be 25,000.

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As Nick Clegg stood back and watched following another impressive show in the televised event, Mr Cameron was joined by shadow cabinet members in urging Mr Brown to apologise and censure candidates who had distributed the leaflets.

But an unrepentant Labour insisted the tactic was legitimate because of "holes" in the Conservative manifesto and comments made by senior Tories before the manifesto was published.

The party claimed the failure of the Conservatives to commit to retaining the winter fuel allowance and other policies made assumptions about their intentions fair game.

Labour insisted the leaflets were no longer being published, but, according to the independent website www.thestraightchoice.org, which logs election campaign literature, some were still being delivered to Scottish homes as recently as 20 April, one week after the Conservatives' manifesto set out their plans.

Speaking hours after he accused the Prime Minister of peddling lies during a debate most observers said was too close to call, Mr Cameron said he had been angry about the information on Labour leaflets "for weeks".

"The Prime Minister now is wriggling and squirming because he has been found out and if he has a moral compass, he should withdraw the leaflets, stop making these claims and stop frightening people," Mr Cameron said.

Earlier, a Conservative press briefing held in the wake of the televised debate said Labour's campaign was based on "pessimism, fear and smear, and the politics of the past that the British people comprehensively want to reject".

In Scotland, the shadow Scottish secretary David Mundell attacked the claims about Tory policy on child tax credits that were made by Alistair Darling in a publication called Local Voice distributed around his constituency.

Mr Mundell said the Chancellor had resorted to "fears and smears to scare young families" about the implications of a Conservative election victory.

"Why are they deliberately lying on their literature?" asked Mr Mundell. "Are they prepared to say sorry for the leaflet lies and the disgraceful campaign that Labour has been running in Scotland?

"Labour's election has been negative, dishonest and has been deliberately targeted at the most vulnerable people in our society including the elderly, the low paid and families."

The Tories were not the only party unhappy with Labour's literature in Scotland. Shortly after the debate, SNP leader Alex Salmond appeared on the BBC brandishing a leaflet circulated in Gordon Brown's constituency claiming the Nationalists wanted to cut free bus travel – a claim the SNP denies.

Labour insisted that a decision by the SNP-led Fife Council to scrap the Fife concessionary travel scheme in February justified the allegation, and accused the First Minister of resorting to "fantasy and smears".

On the Tory claims, Scottish Labour pointed to a leaflet distributed by Peter Duncan, the Conservatives' candidate in Dumfries and Galloway, that claimed Labour was set to cut disability allowance, a claim the Labour Party derided as "lies" and "scaremongering". But the Tories insisted it was based on plans outlined in a Labour green paper.

Meanwhile, Labour big hitters defended the party's campaign strategy after election co-ordinator Douglas Alexander conceded the leaflets had been distributed by "a few" candidates.

Despite claiming he had not authorised the literature, Gordon Brown insisted his party was "right to ask the question" of Tory policy on free prescriptions and eye tests in England, insisting that the Conservative manifesto was "full of holes".

Referring to pledges made by Mr Cameron during proceedings on the Sky debate, Mr Brown said the decision to firm up Conservative policy had been made in a "panic".

"This has had to be forced out of the Conservatives," he said. "They haven't been straight with the British people."

• Claim and counter-claim over Labour's leaflet