Former MP Olivia Chow is making a comeback to the NDP ahead of the upcoming federal election.

Chow announced Tuesday she was running in the new Toronto riding of Spadina-Fort York.

"I believe every one here deserves the positive change an NDP government can bring," she said. "I'm ready to bring my leadership and my experience as part of that change."

Chow vowed, if elected, to work for a national transit strategy, as well as a national childcare program, among other NDP priorities.

NDP Leader Tom Mulcair, who stood beside Chow as she announced her plans, called her a "tireless champion" of Toronto and the issues that are important to its residents.

Chow left her seat in the House of Commons to run in last year's Toronto mayoral election. She finished third.

Following her municipal defeat, she took up a teaching job at Ryerson University as a visiting professor in the Faculty of Arts.

The university announced Tuesday that it agreed to grant her request for a leave of absence, thanking Chow for her "enthusiastic contributions" since her appointment in February.

Chow started her political career as a Toronto school board trustee in 1985 before switching to city hall, where she became known for her work on homelessness and other urban issues.

When she made the leap to federal politics, Chow represented a downtown Toronto riding in Parliament for nearly nine years, working alongside her late husband, iconic NDP leader Jack Layton.

In the upcoming campaign, Chow will face off against Liberal MP and former Toronto city councillor Adam Vaughan.