Peter Ladner, left, and Gregor Robertson took part in their second debate at Science World Wednesday night. (CBC)

The massive cost overruns on the athletes' village under construction for the 2010 Olympics was the hot topic at the second debate between the two main candidates seeking the mayor's job in Vancouver.

On Wednesday night at Science World, Gregor Robertson of the Vision Vancouver Party squared off against the Non-Partisan Association's Peter Ladner in a debate dominated by questions about the massive Olympic housing project in southeast False Creek, which is facing cost overruns of at least $60 million.

Ladner, who voted for the project in his currently role as a city councillor, was asked if taxpayers would be on the hook for the extra costs.

He said he's hoping the private sector developers of the project will be able to finance the overruns, but confirmed there is a so-called 'doomsday' plan for the city to underwrite the losses if required.

"It will be backstopped by the city if it has to be. But there are ways of doing that without providing a load on the taxpayers," Ladner said.

When asked if he would support a taxpayer bailout of the project, he said, "When you say taxpayer bailout it sounds like there would be a big increase in taxes to pay for it. That is not in any of the options I've seen."

Project a risk, says Robertson

During the debate, Robertson, a former NDP MLA, lambasted Ladner's NPA for scrapping the original plans for expanded social housing on the site after the Olympics, saying the decision to go with more high-end housing has now backfired.

"It's put us on a riskier course, because we now have a luxury development with the market softening, and a lot more vulnerability for the viability of that project," said Robertson.

"I think it also gave up on some really important affordable housing. We know we have a desperate situation in Vancouver. We need child care and more community centre space. All of those were given up in this project," he added.

The athletes' village is being built by Millennium Development Corporation, which bought the 32-hectare site on the shores of False Creek from the city. After the Olympics, the condominium units will be sold. Some residents have already put down pre-sale deposits on the unfinished project.

Ladner and Robertson will have another chance to debate on Oct. 22 when the focus will be on affordable housing, homelessness and mental health.

The election is scheduled for Nov. 15.