OTTAWA - Ontario MP Kellie Leitch's bid for the leadership of the Conservative party has been dealt a major blow with the arrest of her campaign manager on impaired driving charges.

Nick Kouvalis has now resigned from his role at the helm of an already highly developed plan for Leitch to seek the Tory leadership.

The 40-year-old was charged Sunday with impaired driving and having a blood alcohol content over the legal limit following a car crash near Windsor, Ont.

Kouvalis says he's been struggling with alcohol addiction since 2011 and had been hopeful that with rehab and regular attendance at AA meetings, he had it under control.

But he says the incident makes it clear he does not.

In a statement, Leitch says she respects Kouvalis for addressing the issue and wishes him and his family all the best.