Patrick Brown's entry into the Ontario Progressive Conservative leadership race could lead to ruthless infighting, leaving the party at a disadvantage, experts say.

"This is a time when the party should be taking all its resources and throwing them at Kathleen Wynne," Jim Warren, a political strategist who has worked with the Ontario Liberals, said this week.

"Instead, they've got the guns pointed at each other and are about to have a 'shootout at the OK Corral.' You will see this real insider fighting — political fratricide, if you will — of the leaders turning on each other."

Brown entered the race on Friday, just weeks after he resigned in the wake of allegations of sexual misconduct made by two women and first reported by CTV.

The other four leadership candidates, preparing for opponents with roughly similar political advantages, will now have to revise their game plan to focus on Brown. The former leader already has a base of support and extensive political experience.

"He's been the leader for the last two years. He has sold a lot of the memberships to the members now. Are they PC members or Patrick Brown members?" Warren said.

The candidates battling to lead the Ontario PC party are, from left: Christine Elliott, Tanya Granic Allen, Doug Ford and Caroline Mulroney. (The Canadian Press/Drafttanya.com)

Either way, Brown's entry into the leadership race is a gift to the Ontario Liberals, according to Jaime Watt, executive chair of the public relations company Navigator and a long-time Conservative strategist.

"I think it harms all the candidates at an important time in Ontario's history," Watt said.

"If I were (Kathleen Wynne) I'd be running to the convenience store to buy a lottery ticket."

Brown registered as a candidate just before the 5 p.m deadline on Friday. He had previously launched an online campaign to discredit the allegations that led to his resignation Speaking to reporters outside PC headquarters, Brown said that he believed his name was cleared.

His entry into the race came hours after interim leader Vic Fedeli announced that Brown was kicked out of caucus, prompting questions about his eligibility to run. Party executives will review his candidacy bid and make a decision in coming days.

Many asking if Patrick Brown is eligible to run for leader after being kicked out of caucus. Unless the party also revoked his membership, that shouldn’t stop him, according to these eligibility rules: <a href="https://twitter.com/hashtag/onpoli?src=hash&ref_src=twsrc%5Etfw">#onpoli</a> <a href="https://twitter.com/hashtag/pcpo?src=hash&ref_src=twsrc%5Etfw">#pcpo</a> <a href="https://t.co/oex2V18fpC">pic.twitter.com/oex2V18fpC</a> —@CBCQueensPark

Nelson Wiseman, a political science professor at the University of Toronto, said the outcome of the executive review is uncertain at best.

"Although he's still a member of the party, the party could suggest he's not in good standing, which is one of the conditions you have to have to run," he told CBC Toronto.

But several PC candidates, at least one MPP and many party members have publicly expressed support for Brown, a sign that a grassroots movement could be mobilizing to bolster his bid.

"There is an awful lot of members I see on social media who think there was an injustice done to him — that he wasn't treated fairly by the party establishment and by the caucus members. So the grassroots members may very well turn on the party elites and try and send in Patrick Brown," he said.

The party membership will vote electronically for its next leader between March 2 and March 8, with results to be announced on March 10.