With up to four million Australians tipped to tune into the MasterChef final, the traditional televised campaign debate between the nation's leaders has taken a back seat.

The debate is traditionally televised at 7.30pm on the first Sunday after election writs are issued, but faced with the cooking show's pulling power the politicians are coming in an hour early.

Sky News political editor David Speers has been confirmed as the debate's moderator, but its participants have been warring over how many should be held.

Labor is keen for the traditional single debate, but the Liberal Party has refused to commit to anything because it is still demanding that Labor honour a promise Kevin Rudd made during the 2007 election campaign that there would be three debates during the "election season".

Mr Rudd said later that the election season did not mean the campaign.

Since he was deposed, Labor has defaulted to the position of previous governments that there be just one debate.

It points out that the Liberals, when in government, allowed only one debate when Labor, in opposition, demanded three.

The ALP national secretary, Karl Bitar, and the Liberal Party federal secretary, Brian Loughnane, have been unable to agree.

Mr Loughnane said not having three debates showed the Prime Minister, Julia Gillard, "does not have a plan for the future".

There has already been one leaders' debate: the health debate between Mr Rudd and Tony Abbott earlier this year which Mr Rudd won easily.

The Liberals say that does not count as one of the three.