Toronto's outspoken chief planner, Jennifer Keesmaat, is leaving her post after a five-year run that saw her clash with Mayor John Tory on various policies, including over the high-profile question of whether to tear down part of the Gardiner Expressway.‎

Easily the city's highest-profile civil servant, using Twitter to express her views on condo development, bike lanes and other issues, Ms. Keesmaat will end her role as Toronto's chief planner on Sept. 29.

In an interview with The Globe and Mail, Ms. Keesmaat said that after five‎ years – she was hired in 2012 during the tumultuous term of mayor Rob Ford – she felt it was time to move on. Ms. Keesmaat said she does not have another job lined up and is only beginning to explore her options.

Story continues below advertisement

‎"I really felt like I needed to start thinking about my next chapter," Ms. Keesmaat said. "… I feel like I have contributed what I could in this role."

She dismissed any idea that her clashes with the mayor over the Gardiner or the Scarborough subway extension ‎had anything to do with her departure, saying she was leaving on very good terms with Mr. Tory: "The mayor and I, it's no secret, had a very, very rocky start. It was very bumpy in the beginning and it took us both a little bit to get used to each other. But if you look at the last several years … the mayor has been wonderful. He has been willing to tolerate a chief planner who didn't fit in a box."

There have long been rumours that Ms. Keesmaat would make the jump to elected politics. Mr. Tory's former campaign aide Nick Kouvalis, in a series of critical tweets in 2015, accused her of wanting the mayor's job. She was approached to run for Parliament for the federal Liberals before the last election, a source told The Globe in 2015, but she turned the idea down.

On Monday, Ms. Keesmaat, while not ruling it out, said politics are not something she is considering now: "It's difficult for me to imagine that."

Of her accomplishments as chief planner, she said one that stood out was her recent push for reforms to the province's unpopular planning tribunal, the Ontario Municipal Board, which will put more power in the hands of municipal planning departments and local councils. She also cited the city's transit network plan, which includes the Scarborough subway extension and made it possible for the city to secure $4.2-billion in federal transit funding.

In an interview, Mr. Tory called Ms. Keesmaat a "driving force" with a great vision for the city that helped shape his thinking on many issues, including her controversial pilot project to restrict cars on congested King Street.

He said he understood her desire to move on from the chief planner's job, which he described as a "meat grinder" in a city with such a blistering pace of development.

Story continues below advertisement

But he said he did urge her to stay on when she came to tell him the news last week, and also told her he hoped he could still come to her for advice. And he said despite a public clash over the Gardiner in 2015, he and the chief planner worked together well in the years since.

"‎I didn't know how my relationship was going to be with her at the beginning, but it developed into something that certainly I valued hugely," Mr. Tory said. "I admire her a great deal because she pushes the leadership of the city to think forward about the city."

Ms. Keesmaat initially opposed the Scarborough subway extension, preferring light rail. She later produced a compromise plan that backed Mr. Tory's call for a subway, accompanied by the Eglinton East LRT line. And she enthusiastically supported Mr. Tory's call for a downtown Rail Deck Park.

But there is no question that her advocacy – usually on Twitter – landed her in hot water with the mayor and some on council more than once. (In 2012, she tweeted that she found councillors' speeches "insufferable.")

Her most serious clash with Mr. Tory appeared to come over the Gardiner and her repeatedly expressed opinion that the eastern portion of the crumbling elevated expressway should be torn down.

In June, 2015, she was called into Mr. Tory's office for a meeting after publicly contradicting the mayor on that issue. Mr. Tory's preferred option for the Gardiner, known as the "hybrid," called for realigning but maintaining the elevated eastern stretch. Council eventually sided with Mr. Tory.

Story continues below advertisement

Sources told The Globe at the time that at the meeting with Ms. Keesmaat, Mr. Tory made it clear that he thought having his chief planner debate him publicly was inappropriate. The incident led to speculation about her future at city hall, but she remained in her post.

City Councillor Joe Mihevc, who shares many of Ms. Keesmaat's views and once employed her as an aide, said she has been approached by international headhunters acting for other cities and planning firms for years. He called her loss a blow for the city.

"In the case of the Gardiner, she was speaking truth to power," Mr. Mihevc said. "We needed a provocateur. … She pushed us to think at a higher level."