Dr Long had a four-year stint as treasurer of the Canberra Labor Club group and said he believed clubs made a valuable contribution to the community.

"I'm a little concerned about the implications of extending a gambling licence to a for-profit provider, which we haven't done before in Canberra," he said.

Dr Long's position is at odds with the Barr Labor Government's support for allowing poker machines into the casino, as part of a major expansion proposed by Hong Kong-based casino owners Aquis to the city-centre casino site.

The government says it will allow 200 poker machines at the casino, ending the clubs' monopoly on machines in Canberra. But the proposal has become a key election issue, with the Liberals opposing the move, and the clubs pledging perhaps $100,000 or more to fight the government and the Greens. Clubs have filled their venues with anti-Labor and Greens advertising materials, are funding a last-minute advertising blitz, and are supporting former lobbyist Richard Farmer's new Canberra Community Voters party.

Dr Long's intervention is unlikely to upset Labor significantly, given the need to raise the profile of candidates in the Murrumbidgee electorate where Labor has no high-profile or sitting candidates, with the resignation of Simon Corbell.

But Dr Long's fellow Murrumbidgee right-faction candidates Chris Steel, who won the most votes in Labor's preselection, and Jennifer Newman, are likely to be less sanguine at his move, given that Labor candidates must compete among themselves for the two seats (or maximum three) that Labor will win in the electorate.

Dr Long stressed he was expressing a personal view, and said if elected he would push his view in the Labor caucus, and look for extensive consultation through a parliamentary inquiry.

"All I'm doing is saying that I've got concerns about implications of a for-profit provider having a gambling licence. My prime concern is that the incentives for for-profit providers are different to those for not-for-profit providers," he said.

"Economists like me tend to focus on the role of incentives, and there's little incentive for a community club to fail to address issues of problem gambling, but the incentives for a for-profit provider are not well aligned with dealing with problem gambling."

He expressed the view at a Christian social justice committee forum run by the Presbyterian church a week ago, where strong concerns were raised about problem gambling, he said.

Dr Long is at the conservative end of his party. He is an economist who worked as a political adviser to Simon Crean and Joel Fitzgibbon in opposition, and Joseph Ludwig and Stephen Conroy in government. He is a senior research fellow at the Australian Centre for Christianity and Culture at Charles Sturt University.