PM David Cameron warned over TV debate stance
The Labour, Liberal Democrat and UKIP leaders will ask broadcasters to press ahead with general election TV debates even if David Cameron refuses to take part.
Ed Miliband, Nick Clegg and Nigel Farage have written to Mr Cameron saying it would be "unacceptable" for the prime minister to refuse to appear.
Mr Cameron has said he will take part only if the Green Party is included.
Nick Robinson reports.
14 Jan 2015