John Tory's announcement came shortly after the Toronto Star newspaper reported he had an affair with the 31-year-old woman—whom he did not name.

He said the affair started during the Covid-19 pandemic and was "ended mutually by consent this year."

The 68-year-old called the relationship "a serious error in judgement."

In a statement Tory said: "I am deeply sorry, and I apologise unreservedly to the people of Toronto, and to all of those hurt by my actions.

"Most of all, I apologise to my wife, Barb and to my family who I've let down more than anyone else," he added.

John Tory took office in December 2014.