TORONTO - Caroline Mulroney is sharpening her attacks on her rivals in the race to lead Ontario's Opposition even as she urges them to support her calls for the party's former leader to back out of the contest.

The Toronto lawyer and businesswoman took aim at two of her competitors, Christine Elliott and Doug Ford, in a news conference ostensibly aimed at getting them to side with her against Patrick Brown.

Mulroney has urged Brown to abandon his bid to reclaim his old job, which he gave up late last month amid sexual misconduct allegations he maintains are false.

Both Elliott and Ford have so far said they're focused on their own leadership campaigns since the party gave Brown the green light to proceed in the contest earlier this week.

On Friday, Mulroney questioned Elliott's commitment to the Progressive Conservatives, saying the former health-care ombudsman gave up on politics to take a high-profile job from the governing Liberals.

She also criticized Ford's fiscal savvy, saying his "on-the-fly" policies would cost the province billions of dollars.