Gordon Brown today finally signalled that he is ready to take part in a series of television debates with the other main party leaders.
In a letter posted on the Labour Party website, the Prime Minister said he believed there should be a "strong focus" on the leaders' debates in the run up to the general election.
But the plan hit an early snag as the Scottish National Party issued a warning that it would seek to block the screening in Scotland of any debate which did not include its leader, First Minister Alex Salmond.
SNP election campaign co-ordinator Stewart Hosie said that it would be "entirely unacceptable" if the party was frozen out in a three-way debate between Mr Brown, Tory leader David Cameron and the Liberal Democrats' Nick Clegg.
The party's intervention potentially opens the door to similar demands from other smaller parties contesting the election which could scupper the whole project.
The BBC, ITV and Sky announced yesterday that they had set up a joint team to discuss with the parties a proposal for a series of three debates featuring the three main leaders.
In a statement they said that they would each seek "to make suitable arrangements for ensuring due impartiality across the UK", but did not explain how that would be achieved.
Mr Hosie said that while the SNP were prepared to be flexible about the format that was adopted, they must as a matter of principle be included in any debate.
"The broadcasters must meet their obligations to audiences across the UK - and that means that any debates broadcast in Scotland must include Alex Salmond, and other relevant spokespeople should there also be subject debates," he said.
"We shall be approaching the broadcasters to demand such guarantees, given their clear public service obligations to ensure fairness and impartiality in election-related coverage in Scotland.
"It would be entirely unacceptable for the leader of a party not just represented at Westminster but which is also the government of Scotland to be excluded from any such debates."
In his letter, Mr Brown acknowledged that the details of the debate would have to be thrashed out. He made clear, however, that he would like to see a wider series of debates, on both television and radio, featuring the main party spokesmen across a range of issues.
"It is right that there will be a strong focus on the leaders' debates and it is right that in a Cabinet system of government that ministers and opposition ministers also debate the issues in a series of debates on television and radio too," he said.
"I relish the opportunity of making our case directly to the people of this country."
If the televised leaders' debates do go ahead, they will be the first in British political history.
Mr Cameron and Mr Clegg have already declared their readiness to take part. It was reported that Mr Brown was going to announce his acceptance at the Labour Party Conference in Brighton, but apparently drew back fearing it would overshadow the rest of his message.
His signal now that he is prepared to debate live on camera with his main rivals was welcomed by both the Conservatives and the Lib Dems.
"David Cameron welcomes this news and is very pleased that after months of dithering on this the Prime Minster has finally committed himself to the leaders' debates," a Tory spokesman said.
Mr Clegg said: "People have become fed up with the discredited and out of date way politics is conducted in Westminster. These debates are a great way to seek to build bridges between politicians and people."Reuse content