LONDON -- David Cameron has made his "final offer."
After much speculation and negotiation the prime minister said late Wednesday evening he would participate in only one televised debate ahead of the general election in May.
In a letter to broadcasters, Cameron said he won't partake in a head-to-head debate with Labour leader Ed Miliband, but agreed to a seven-way leaders' debate.
The BBC, Channel 4, Sky and ITV had proposed three separate debates, two involving the Conservatives, Labour, the Liberal Democrats, UKIP, the Greens, the SNP and Plaid Cymru, and a third debate between just Cameron and Miliband.
Cameron's director of communications told broadcasters the one and only debate would have to happen before the dissolution of parliament, the week ending March 30, and could be 90-minutes long.
But the other parties and the broadcasters appear to be holding firm on more than one debate.
Following reports Wednesday night, Lib Dem leader Nick Clegg tweeted:
.@David_Cameron The British public want the debates so let's get on with it. Stop holding them to ransom by trying to dictate the terms.— Nick Clegg (@nick_clegg) March 4, 2015
While on Thursday morning, former Lib Dem leader Paddy Ashdown said if Cameron won't do the head-to-head debate, Clegg could stand in for him against Miliband.
"I’m told that Downing Street is now depending on the Liberal Democrats to say no. Well, I’ve got bad news for them. We’re not going to," Ashdown told BBC Radio 4's Today programme.
Labour's chair of general election strategy Douglas Alexander said the party would continue to support the proposals for a two-way debate as well as a seven-way debate.
"This is an outrageous attempt from the Prime Minister to bully the broadcasters into dropping their proposals for a head-to-head debate between David Cameron and Ed Miliband," he said in a statement.
“That it comes only hours after Ed Miliband called David Cameron’s bluff and said he would debate him any time, any place, shows the lengths David Cameron will go to run scared of a debate with Ed Miliband.”
Reacting to the Conservatives proposals, the broadcasters issued a joint statement, saying they'd respond in due course.
"The broadcasters are committed to providing our audiences with election debates. 22 million people watched the debates in 2010 and we believe the debates helped people to engage with the election," it said.
"The broadcasters have set out their proposals and continue to talk to all the relevant parties on an equitable basis."