Poll: Should David Cameron take part in all the leaders' TV debates?

It follows David Cameron's refusal to take part in the three showdowns proposed by broadcasters.

Mr Miliband will move to put "fair and impartial leaders' debates" on a statutory footing in an effort to avoid them becoming subject to the kind of political wrangling that has characterised the programmes scheduled for next month in the run-up to polling day.

The new system would work on similar lines to the current rules for planning the number, length and timing of party political broadcasts.

That would mean parties are consulted but not given the right to veto the debates taking place.

Labour believes this could be done by establishing the Broadcasters' Liaison Group as a trust in statute so it is the recognised legal body for deciding dates, format, volume and attendees of the debates.

Mr Miliband told The Observer: "In recent days the British public has been treated to the unedifying and tawdry spectacle of a prime minister seeking to duck out of the TV debates he once claimed to support with great enthusiasm."

He said the broadcasters had " made it clear they would not be cowed by his tactics but it is wrong for them and the British public to have governing parties use this kind of pressure in campaign periods".

Mr Miliband added: "It is time to ensure, once and for all, that these debates belong to the people, not the prime minister of the day."

The four broadcasters - the BBC, ITV, Sky and Channel 4 - have said they will stick to their previously-announced plans for three debates during the election campaign, and urged the Prime Minister to "reconsider" his refusal to take part in these shows, including a head-to-head showdown with Mr Miliband.

But Mr Cameron's chief spin doctor Craig Oliver said their response was "disappointing" and restated the Prime Minister's "final position" was for a single debate to take place in the week starting March 23.

The broadcasters said they would stick to plans for a seven-way debate involving Mr Cameron, Mr Miliband, Nick Clegg of the Lib Dems and the leaders of the Greens, Ukip, Scottish National Party and Plaid Cymru on ITV on April 2, followed by a second show on BBC featuring the same line-up on April 16.

A final one-on-one clash with the Tory and Labour leaders invited is scheduled to be broadcast on Sky News and Channel 4 on April 30 - exactly a week before the May 7 election.

In a letter to Mr Oliver, the broadcasters made clear they were ready to go ahead with the debates even if Mr Cameron decides not to take part.