Ottawa mayoral contenders Mark Sutcliffe and Catherine McKenney are in a statistical tie, a Mainstreet poll suggests.

Across three polls, in July, September and October, McKenney's support has held steady at 34 per cent.

In July and September, that made McKenney the clear frontrunner. In the October poll, however, Sutcliffe narrowed the gap, with 32 per cent support, a dramatic change from 15 per cent in July and 20 per cent in September.

The rise in Sutcliffe's support lines up with a fall in the number of undecided voters.

"Generally, there's a bit of a ceiling with progressives in Ottawa," said Mainstreet analyst Robert Martin. "And that ceiling is about the 34 per cent that McKenney is at."

"Centrist voters were just kind of sitting on the sidelines, not sure which candidate to pick. And some bigger Liberal names have endorsed Sutcliffe recently. They didn't know where to go before. And I think they've kind of found their home now."

For instance, Ottawa Centre Liberal MP Yasir Naqvi recently endorsed Sutcliffe.

University of Ottawa political scientist Daniel Stockemer expects the downtown to back McKenney, rural areas to back Sutcliffe, and the suburbs in between to be to a certain extent in play.

"The area where it will be decided is probably somewhere like Alta Vista, where votes can go both ways."

McKenney is "probably too progressive for a lot of folks in the suburbs, and for a lot of folks in Kanata or Barrhaven," he said.

Sutcliffe needs to appeal to centrist voters to win.

"He probably has all the votes to the right, and McKenney's very strongly to the left. Strategically, where he can get votes is in the middle."

On the other hand, Stockemer pointed out, McKenney earned the loyalty of many downtown voters during the convoy occupation last winter, and he expects them to turn out in large numbers.

"It matters a lot downtown," he said, adding that people appreciate that McKenney spoke out and seemed to want to do something about the occupation.

"Even in Sandy Hill, people who are a little more tilting toward fiscally conservative, they might still support (McKenney). In the suburbs, the whole convoy was very far from their daily lives."

McKenney is expected to testify in the Public Order Emergency Commission hearings that begin this week.

The poll shows McKenney doing better with younger and university-educated voters, and Sutcliffe doing better with older voters.

It doesn't break Ottawa out by neighbourhood, but Sutcliffe is favoured by people who say they don't use public transit, implying his support is more rural and suburban than McKenney's.

Advance poll turnout is higher than in 2018, and was highest in wards in or closer to downtown.

"The hunch I have is that McKenney will win because I think turnout will be high in the inner city," Stockemer said.

This Mainstreet Research poll was conducted on Oct. 7, 2022. A sample of 1,141 people was interviewed by automated telephone interviews. The poll is accurate to within ±2.9 percentage points, 19 times out of 20.

Mainstreet Research is part owner of iPolitics and QP Briefing.

Poll shows dramatic shift in tightening Ottawa mayoral race

Read this for free.