UK broadcasters are expected to confirm that the first TV election debate featuring the party leaders will go ahead next week, with David Cameron and Ed Miliband interviewed separately by Jeremy Paxman.
It is thought that the announcement on Thursday will also confirm the formats for the rest of the debates, and that there are unlikely to be substantial changes to the proposals which Downing Street claimed on Tuesday to have agreed with broadcasters.
In the first programme, to be broadcast jointly on 26 March by Sky and Channel 4, Paxman will interview the prime minister and the Labour leader separately, with questions from a studio audience.
The following week they would share a stage in a seven-way debate along with the leaders of Ukip, the Green party, the SNP, Plaid Cymru and the DUP.
To the fury of Labour, the Tories briefed the details of the deal on Tuesday, agreed after direct negotiations between the broadcasters and Downing Street.
On Wednesday night, a senior Labour source said the party was still calling for a one-on-one debate between Miliband and Cameron. “We want the debates the British people want – a head-to-head between Ed and Cameron. The easy answer to this is for Cameron to stop chickening out,” he said.
The deal also envisages “a challengers’ special” involving the SNP, Ukip, Plaid Cymru the Greens and the DUP, to be broadcast by the BBC on 16 April.
Finally, on 30 April, Cameron, Miliband and the Liberal Democrat leader, Nick Clegg, would appear separately in half-hour segments in a Question Time-style event hosted by David Dimbleby on BBC1.
The plans appear to have emerged from back-channel negotiations at the weekend.
Broadcasting sources confirmed that the announcement would be made on Thursday morning.
