If someone had predicted a few months ago that Olivia Chow would emerge as the most fiscally responsible candidate for mayor, a snort of derision would have been a typical and understandable response.

Ms. Chow, after all, is a stalwart of the NDP, the party usually associated with big government. Her rivals, John Tory and Rob Ford, were big-C Conservatives, the first a former leader of the provincial Progressive Conservative Party, the second a self-described champion of the taxpayer.

But a lot of water has flowed under the bridge since the campaign got under way early this year. Mr. Tory rolled out a big and expensive transit plan, SmartTrack, and said he could get it built without raising local taxes. Rob Ford rolled out an even bigger, more expensive plan for a network of new subways. He, too, said he could get it done without raising taxes. His brother Doug is running on essentially the same transit-for-nothing plan.

Story continues below advertisement

Ms. Chow's platform looks modest and cautious in comparison. Her promises to increase bus service, expand child nutrition programs and study a new central subway line come at a reasonable cost. She would raise money to cover her pledges by hiking land-transfer taxes on properties worth more than $2-million.

She admits that paying for the subway line may mean higher property taxes down the line. She would try to cancel an expensive subway extension in Scarborough and go back to the original plan to build light-rail, a plan that would be funded by the provincial government instead of the city. She says she would keep property taxes while she is mayor around the rate of inflation.

At a meeting with the editorial board of The Globe and Mail on Thursday, Ms. Chow said it was "ironic that you have the so-called NDP candidate" emerging as the more frugal candidate. "You can't go and say that you can borrow billions of dollars and somehow, somewhere, that the money would come. That's fiscally irresponsible," she said.

She promised to keep hammering away at Mr. Tory's transit plan and his proposal to use tax increment financing to pay for it. She says it relies on unrealistic assumptions about the amount of development the line would attract and the levels of incremental tax revenue it would bring in. She produced a study by an economist to back up her claim. She notes that she has published a fully costed platform "so in terms of fiscal conservative, I am the one that actually will tell you where the funds will come from."

Whether voters will buy it is hard to say. Some don't trust her to keep her promises, worrying that she will revert to NDP stereotype and become a heedless spendthrift once she has the chain of office around her neck. Some voters on the left, by contrast, think that she is worrying too much about the bottom line and failing to show sufficient ambition. Many voters in Scarborough, meanwhile, feel that cancelling the subway extension would short-change them. Reverting to light rail would save the city money, yes, but it would unravel a plan backed by three levels of government and rekindle a debate that many thought was settled.

Ms. Chow often says that as a struggling teenaged immigrant from Hong Kong, she learned to be careful about money. She often pores over the numbers produced by her staff to make sure it all adds up.

She says that while she cares about helping the less fortunate and believes in investing in the city, she is also "practical and sensible … honest and realistic." Given her record during this campaign, that claim is nothing to snort at.