His hopes of winning another term in tatters, Toronto Mayor Rob Ford left his city to seek treatment for substance abuse a day after a second video emerged that appears to show him puffing from a crack pipe.

Political observers say the populist mayor, who was elected four years ago on a wave of support from Toronto's conservative suburbs, has no chance of winning October's election.

But in the conservative, ethnically diverse suburbs that elected him and where his promises to slash spending, cut taxes and end what Mr Ford has called "the war on the car" are treasured, some die-hard loyalists are sticking by him.

"He's been involved with the people, he wants to save people money," said Kalyan Gohain, 43, a sales executive who lives in Mr Ford's suburb of Etobicoke.

But Sairah Nazir, 34, a mother of two who lives in Etobicoke, said she will not vote for Mr Ford again.

"He may take a decision that's not in the best interests of our community when he's not in his right mind."

The experts, for the most part, agree that Mr Ford's days in politics are almost certainly over, in the near future at least, and it is only the constant media attention that has created a false impression that his political support remains strong.

"Because he's such a fascinating individual, he's a perfect storm for the media, and for people who are taken with celebrities," said Nelson Wiseman, a political science professor at the University of Toronto.

"But the people who want selfies with him are looking for entertainment. Those are not people who are going to go door to door for him."

Mr Ford announced on Wednesday that he would take leave for an unspecified amount of time from both his mayoral post and his re-election campaign, but he did not abandon his bid for a second term as mayor of Canada's second largest city.

A day after announcing his decision, he boarded a plane for Chicago headed for a treatment programme that will last at least 30 days, his lawyer Dennis Morris said.

Mr Ford's family business, Deco Labels and Tags, has a plant in the Chicago area and his brother Doug has a second home there.

Doug Ford said his brother would enter a 30-day inpatient treatment at one of the best rehab facilities in North America but he declined to name the location.

Mr Morris said the 30 days could be extended.

Mr Ford has for months been the subject of a drug-related police investigation, but he has not been charged with any crime. The Toronto City Council stripped him of most of his powers last year.

In a statement on Wednesday, he admitted having a problem with alcohol and said he would seek help - but he did not address the reported video or make any reference to crack cocaine.

"I have a problem with alcohol, and the choices I have made while under the influence," he said.

"I have tried to deal with these issues by myself over the past year. I know that I need professional help and I am now 100% committed to getting myself right."

The Globe and Mail newspaper said it has viewed a second video of Mr Ford smoking what appears to be crack cocaine in his sister's basement.

Toronto police said they were looking into the new video.

News reports of an earlier video of Mr Ford apparently smoking crack first surfaced last May.

The mayor denied the existence of that video for months but after police said they had obtained it, he admitted that he smoked crack in a "drunken stupor."

He rebuffed intense pressure to resign and launched his re-election bid earlier this year.

In a letter to the city clerk, Mr Ford did not specify the length of his leave, saying only that he will provide updates on his status, according to Jackie DeSouza, a spokeswoman for the City of Toronto.

Mr Ford has careered from one scandal to another, including public drunkenness and threatening "murder" in a videotaped rant.

His friend and former driver Alexander Lisi is facing extortion charges over alleged attempts to retrieve the first crack video from an alleged gang member.

On Wednesday, The Toronto Sun said that it had obtained an audio recording of Ford making offensive remarks about other politicians at a bar on Monday night.

Another candidate in the October 27 race, John Tory, said the mayor should resign "for the good of the city."

City Councilor John Parker said Ford should "go and never come back. Things have gone too far."

Canadian Prime Minister Stephen Harper's office said Mr Ford's "comments and behaviour are very troubling" and they "are pleased to hear the Mayor has entered rehab".