Mayor Larry O'Brien's communications director is seeking the Progressive Conservative nomination for Ottawa West-Nepean in the upcoming Ontario election — a move that at least one councillor thinks could hurt the mayor at a sensitive time.

"I’m very excited about this," said Mike Patton Tuesday, adding that he planned to leave immediately after helping O'Brien with a scheduled regional mayors summit on Wednesday.

"After that I’ll be working on the nomination because … the nomination is by no means a certain thing.”

Ottawa West-Nepean has been held since the 2003 election by Liberal Jim Watson, who is currently the minister of health promotion.

Challenging Watson will be a "huge uphill battle," Patton agreed. But he said he's grown up in the riding, lived there his whole life, and put together a good team to help with his bid.

'He'll feel it right away and that will be regardless of whether Mike wins or loses.'— Coun. Rick Chiarelli

Earlier, Coun. Rick Chiarelli, for whom Patton worked before helping on O'Brien's successful mayoral election campaign, said Patton talked about running for the nomination more than a year ago.

But he didn't expect Patton to resurrect the idea now.

"I was surprised because of all the circumstances at city hall and the upheaval and change going on in the mayor's office," Chiarelli said.

O'Brien's chief of staff, Walter Robinson, left his post just days ago, and the mayor has also been facing resistance from council over his plans to keep taxes frozen and to change the way city hall does business over the next few years.

Patton is one of the few people in the mayor's office with previous municipal experience, and Chiarelli said Patton's departure would be a blow to the mayor.

"He'll feel it right away, and that will be regardless of whether Mike wins or loses," said Chiarelli. "Mike knows how to operate with the media to get the focus moved to the best possible position it can be for the mayor."

Ontario voters go to the polls on Oct. 10.