The mayor of Canada’s largest city has stepped down after acknowledging he had an affair with a former staffer.

Toronto Mayor John Tory said at a late Friday night news conference that he developed a relationship with an employee in his office.

The 68-year-old was known as a straight-laced, buttoned-down moderate conservative — almost the polar opposite of previous Toronto Mayor Rob Ford, whose term was plagued by scandals involving public drinking and illegal drug use.

“I recognize that permitting this relationship to develop was a serious error in judgment on my part,” Tory said after the Toronto Star reported on the affair.

“It came at a time when Barb, my wife of 40-plus years and I were enduring many lengthy periods apart while I carried out my responsibilities during the pandemic,” he said.

“As a result, I have decided I will step down as mayor so I can take the time to reflect on my mistakes and to do the work of rebuilding the trust of my family.”

Tory was first elected mayor in 2014, in part on a promise to restore respectability to the office after the turbulent term of Ford. Tory recently won a third term.

Rob Ford’s four-year tenure as mayor of Canada’s largest city was marred by his drinking and crack cocaine use. He later died from a rare form of cancer.

Tory said he is “deeply sorry” to the people of Toronto.