The fate of Prime Minister Kevin Rudd will go down to swing voters and preferences, his Liberal National Party rival Bill Glasson says.

"It is probably a line ball," Dr Glasson said Saturday.

"The reality is there is probably seven or eight per cent of voters still undecided this week and my fate and Mr Rudd's fate lies in their hands.

"It is going to be extremely close and I think it is going to come down to preferences.

"It wouldn't surprise me if it is a late result."

Mr Rudd was elected to the Brisbane seat of Griffith in 1998 and holds the seat by an 8.5 per cent margin.

"It is a huge swing. I'm not confident. I'm confident we worked hard and got out message out there," Dr Glasson said.

"To get it in the incumbent prime minister's seat makes it even harder, so I wouldn't draw any conclusions at the moment."

Dr Glasson, the former president of the Australian Medical Association, has lived in the electorate his entire life and believes some voters see the prime minister as an absent member.

He also expects a backlash over the economy and Labor's leadership changes.

"We've done a lot of door knocking and there is a clear feeling there that they have had enough and they want a change."