The Labor and Liberal parties have agreed to Sunday, August 11 for the first leaders’ debate of the campaign - but there is no agreement on the venue or format.

Since the start of the campaign, Prime Minister Kevin Rudd has suggested each major TV network should host a debate during each week of the campaign. The Liberal Party has suggested one debate at the National Press Club this Sunday and then two public forums in Sydney's Rooty Hill and Brisbane.

On Wednesday, Labor's national secretary, George Wright, wrote to his Liberal Party counterpart, Brian Loughnane, to "accept" Mr Loughnane's offer of a Sunday debate. But Labor is suggesting this takes place in Sydney, hosted by Channel 7 in conjunction with Facebook. Labor is also suggesting that the same opportunity is then given to all the other major networks.

Mr Loughnane has since replied, insisting that the August 11 debate takes place at the National Press Club in Canberra and be open to all media - as well as taking questions from "ordinary Australians" via social media.

The Liberal Party’s federal campaign director also noted that Mr Rudd had not responded to Mr Abbott’s proposal for the two public forums.

Both leaders have been firing multiple shots at each other over the lack of agreement on the debates issue.

This week, Mr Rudd was at pains to point out that he was debating the Liberal National Party candidate for Griffith, Bill Glasson, on Tuesday morning. "If the Liberal candidate for Griffith can stand up and debate as the local member ... why can’t Tony Abbott?"

Mr Abbott has said that it was important the election debates engage the voting public.

"It's very important that his election campaign is not some insider bubble, where Tony Abbott, Kevin Rudd and a few journalists argue with each other. There's got to be an engagement with the people," Mr Abbott said on Monday.

The two leaders continued their "debate about the debates" via Facebook on Wednesday.

Mr Rudd posted on the social media site: "Why won't Tony Abbott accept a debate with me and the 11 million Australians on Facebook participating? KRudd" and gained about 4,000 "likes" as of Wednesday afternoon.

Mr Abbott posted on Facebook: "I look forward to debating Kevin Rudd this Sunday at the National Press Club, including taking questions from social media from people across Australia."

In a later post - featuring a picture of the Coalition Leader posting his message about the Press Club debate - Mr Abbott's team writes: "SHARE this if you support real change in Australia." The comment has received more than 3,000 "likes" and more than 500 "shares".

On Wednesday afternoon, a spokesman for Mr Rudd said that negotiations were continuing between the Labor Party and the Coalition and that the Prime Minister hoped to see an outcome "soon".

"The Prime Minister has made clear several times that he wants to debate Tony Abbott at least once a week during the election campaign," the spokesman said.

"Mr Rudd believes voters deserve the opportunity to hear from both leaders about their plans for the future."

If Labor's Channel 7/Facebook debate goes ahead, it would be the first time a social networking site has been directly involved with a televised federal election debate.

"The involvement of Facebook will facilitate greater participation from young people," Mr Wright said in his letter.

He also said all the major television networks had contacted Labor asking to host debates.

"We have taken up their offer, should Mr Abbott be willing to participate and a suitable time can be found," he said.

Former prime minister Julia Gillard pledged in 2010 to establish a "Leaders' Debate Commission", as part of her agreements with the Greens and independents Tony Windsor and Rob Oakeshott that allowed her to form her minority government.

The independent body would have set the timing, number and process for election debates and removed it from party politicking. No concrete progress was made on the pledge during the 43rd Parliament.

With AAP