Toronto Mayor Rob Ford is endorsing Stephen Harper in the federal election, after initially saying he would not pick a favourite to become prime minister.

"Stephen Harper's platform to lower taxes, to create jobs, to stimulate the economy and build subways in this city is why I am choosing to vote for Stephen Harper and vote for the Conservative party," Ford told CTV Toronto on Friday.

Ford is scheduled to introduce Harper at a Conservative rally in Brampton Friday evening, where he is expected to make the endorsement official.

The event will take place at 7:30 p.m. during which Harper will be joined by local Conservative candidates.

Dr. Duncan MacLellan, a professor of politics at Ryerson University, says it is rare to see a sitting mayor publicly endorse a favourite for prime minister, but could prove to be an effective measure.

"At this late stage in the game it is difficult to determine what the impact could be. I think it might be to help the Conservatives make some inroads into downtown Toronto by having the mayor support him so visibly," MacLellan said.

Ford had previously said he would stay out of the federal election, except to support long-time friend Jim Flaherty's reelection campaign in the Whitby-Oshawa riding.

During a campaign stop on Friday, Flaherty said it makes sense that Ford would offer his endorsement to Harper.

"We are the same," Flaherty said about the federal Conservatives and Toronto's Ford Nation. "We share conservative values. The mayor cares a great deal about infrastructure, about subways in the City of Toronto."

Ford's support for Harper's Conservatives comes as NDP Leader Jack Layton is witnessing his national support rise in poll results.

With just a few days left before Canadians go to the polls on Monday, all the party leaders are strategically trying to shore up support in key ridings.

Both Liberal Leader Michael Ignatieff and Prime Minister Stephen Harper are turning a critical eye on the NDP's policies and platform.

With a report from CTV Toronto's Alicia Markson