The federal government must review the contract for Ottawa's proposed light rail transit line to which it has committed $200 million, says the president of Canada's Treasury Board.

"I want to be convinced that there won't be cost overruns," John Baird told CBC on Thursday.

In July, Ottawa city council approved a $778.2-million contract with Siemens-PCL/Dufferin to design the transit line, build it and maintain it for 15 years. The north-south rail line is to run from the University of Ottawa to Barrhaven Town Centre.

Baird would not say what he would do if potential cost overruns were found.

"I'll cross that bridge when we come to it," said Baird, whose government agency is responsible for overseeing government spending and ensuring value for money.

Baird added that it was Ottawa city council's job — not his — to decide whether the rail project will go ahead.

He also insisted that the government remains committed to providing the money.

But Ottawa Coun. Diane Deans said the fact that the review is happening suggests that the federal government may decide not to provide the money.

"And that sets off a whole new process that in my mind would have the net result of killing the contract," she said.

Mayoral candidate requested review

Since Ottawa signed the rail contract this summer, the rail line has become a hot topic of debate among the frontrunners in Ottawa's mayoral election.

Mayoral candidate Larry O'Brien asked the Treasury Board president to review the federal government's $200-million contribution to the project in a Sept. 21 letter.

Both O'Brien and candidate Alex Munter have said they will conduct a complete review of the north-south line and a possible future east-west expansion if elected.

Meanwhile, incumbent Mayor Bob Chiarelli has said the federal government must produce its contribution to the rail project by mid-October or the city will have to pay contract penalties.

Baird insisted he was not getting involved in Ottawa's municipal politics, and said his review was happening now because that's when the contract came forward for Treasury Board approval.

The former Liberal federal government committed $200 million to the LRT project two years ago.

The Ontario government has also committed $200 million.