Toronto Mayor Rob Ford said Monday that he had been in "complete denial" about his drinking and drug use before entering a rehabilitation clinic two months ago, and admitted that his struggle against substance abuse will never end.

Ford made comments as he returned to City Hall and rejoined a re-election campaign where he is running in second place, according to a recent poll. He took leave on April 30, saying at the time that he needed to deal with an alcohol problem.

"For a long, long time I resisted the idea of getting help. Like a lot of people dealing with substance abuse, I was in complete denial. I had convinced myself that I did not have a problem," Ford told reporters, at points appearing to fight back tears.