Patrick Brown has officially joined the race to lead Ontario's Progressive Conservatives in an effort to reclaim the party's top job, which he was forced to give up last month amid sexual misconduct allegations.

The Barrie, Ont., politician arrived at the party headquarters in Toronto late this afternoon, moments ahead of a registration deadline. Elections Ontario has since listed him as one of five candidates vying for the party's top post months ahead of a spring provincial election.

Earlier on Friday, Brown was kicked out of the Tory caucus, which means he will sit as an independent when the legislature resumes on Tuesday.

Brown has mounted a campaign in recent days to clear his name, alleging two women who spoke out against him in late January were lying and possibly manipulated by his political enemies inside and outside the party. He has also vowed to sue CTV News, which broadcast the allegations. CTV has said it stands by its reporting.

Four other candidates -- former Tory legislator Christine Elliott, Toronto lawyer and businesswoman Caroline Mulroney, former Toronto city councillor Doug Ford and social conservative advocate Tanya Granic Allen -- are already competing to be party leader.

Mulroney and Ford said Brown joining the race pulled attention away from what should be the party's real objectives.

"Patrick Brown made the right decision to step down. A leadership election is not the place for him to clear his name," Mulroney said on Twitter. "Our focus should remain on beating (Premier) Kathleen Wynne in less than 100 days. This is a distraction from that and I am disappointed."

Ford said in a statement that the party is stronger without Brown, citing a boost in fundraising and memberships since the former leader resigned.

"The Ontario PC Party needs to focus on defeating the (Kathleen) Wynne Liberals in June," he said.

Elliott also stressed the importance of unity ahead of the spring election.

"With fewer than 100 days, now is a time for unity. I am the leader that can unite the party and beat Kathleen Wynne," she said in a statement.