TORONTO - Bob Rae will have to wait a while longer for surgery to repair a slowly developing aneurysm in his aorta.

The former Ontario premier was to have had open heart surgery last week.

But a spokesman says Rae caught a cold after attending Nova Scotia Liberal MP Scott Brison's wedding the previous weekend. His doctor decided it would be best to postpone the surgery until Rae was back in good health.

No new date has yet been scheduled for the operation, which is to be performed at the Peter Munk Cardiac Centre.

Rae originally estimated that he'd be able to return to a full  schedule within six weeks. But the delay could make it more difficult for Rae to actively campaign in Toronto Centre should Prime Minister Stephen Harper call a byelection in that riding any time soon.

Rae, who finished third in last year's Liberal leadership race,  was nominated to carry the party's banner in the riding after veteran former minister Bill Graham resigned early in the summer.

The 58-year-old Rae hopes to return to the Commons, where he sat as an NDP member between 1978 and 1982.

He was Ontario premier from 1990 to 1995.

Although Harper has called three Quebec byelections for Sept. 17, he has not yet picked a date to fill four other vacancies, including Toronto Centre. Insiders have said he likely won't call the other four until after the Oct. 10 Ontario election.