David Cameron was challenged to a head-to-head debate by senior pro-Brexit Tories after he accused them of lying to voters about the risks of leaving the EU.
Vote Leave said a hastily-arranged press conference by the Prime Minister betrayed “panic” in the Remain camp and suggested he was “too chicken” to take on opponents directly.
In a joint statement, Michael Gove and Boris Johnson said the public “deserve the chance to hear these issues debated face-to-face between the Prime Minister and a spokesman for Vote Leave so they can judge for themselves which is the safer choice”.
Mr Cameron faces a TV audience later, but separate to Ukip leader Nigel Farage, after declining to be grilled alongside other politicians, citing a desire to avoid “blue-on-blue” clashes.
Ukip MP Douglas Carswell accused Remain and the premier of being in a “blind panic” because the country was “rejecting his campaign of fear”.
“The Prime Minister says we need a proper debate about the facts, but he is too chicken to take on anyone from the Vote Leave campaign head-to-head,” he said.
Justice Secretary Mr Gove and ex-London Mayor Mr Johnson threw down the gauntlet after their party leader summoned journalists to make a fresh assault on the Leave campaign.
Mr Cameron - who claimed he had been inspired to hold a rare press conference after watching the television news - urged voters to “listen to the experts” about the risks of divorce with Brussels.
Forecasts of damage to the UK economy and jobs - including a warning from Hitachi chairman Hiroaki Nakanishi that international investors would “hold back” - were a “reality check”, he said.
But he listed six claims which amounted to “complete untruths” and accused rivals of “complacency and nonchalance” after Mr Gove suggested voters should dismiss assessments of economic experts.
The Prime Minister rejected suggestions that his intervention was a sign of panic over polls suggesting public opinion is swinging towards a Leave vote.
But he said he wanted to ensure that voters did not make their decision on the basis of incorrect information.
Mr Gove and Mr Johnson seized on a decision by the European Court of Justice over the rights of asylum seekers that Brexit supporters said made it easier for illegal immigrants to enter the UK.
“If we needed a reminder of just how risky it is to remain in the EU, the European Court has today issued extraordinary judgments that undermine our ability to deal effectively with asylum,” they said.
“The Prime Minister was absolutely right to hold this vote and allow ministers the chance to disagree with him. We hope that in the same spirit he will accept this invitation.”
Liberal Democrat leader Tim Farron said Britain’s future in the EU was “too important to remain a blue-on-blue slugfest between two chaps who went to Eton 30 years ago”.