Opposition Leader Tony Abbott says he's not afraid of Peter Beattie but Kevin Rudd should be.
Mr Beattie, Queensland premier from 1998 to 2007, will run for Labor in the federal seat of Forde at the September 7 election.
Labor believes the southeast Queensland seat held by Liberal Bert Van Manen is winnable, given its margin of 1.6 per cent.
They also hope Mr Beattie's comeback will lift its chances across the state.
Mr Abbott told reporters in Launceston on Thursday Mr Beattie is a potential leadership rival for the prime minister.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"Another flim-flam man who hit people with record debt and deficit, who is just going to add to the leadership instability in the Labor party," Mr Abbott said of the former premier.
"You might say to me 'Am I worried about Peter Beattie?' Of course not, but I bet Kevin Rudd is."
Earlier, Mr Abbott described Mr Beattie as a "last minute celebrity blow in".
Opposition Communications and Broadband spokesman Malcolm Turnbull said Queenslanders would have to have a collective case of amnesia to vote for Peter Beattie, who had nearly let Brisbane run out of water.
Mr Turnbull said the former Premier's time in office was marked by a neglect of investment in infrastructure in southeast Queensland including delays to the northern water pipeline and the Traveston dam.
"Brisbane came very close to running out of water," Mr Turnbull told reporters in Sydney.
"They've sort of got a unity ticket on not investing and as a consequence there had to be a massive investment at very high prices ... to try and upgrade Brisbane's water supply.
"He must think that the people of Forde have got a collective case of amnesia."
