Erin O'Toole has lost a vote to remain leader of the Conservative Party of Canada.

The party's members of Parliament met virtually today to cast secret ballots after about one-third of them signed a notice that triggered a leadership review.

Ontario MP and national caucus chair Scott Reid said in a statement that 73 Conservative MPs voted to replace him while 45 endorsed him.

There are 119 Conservative MPs, including O'Toole. As caucus chair, Reid said he did not vote.

Conservative MPs must now choose who will serve as the party's interim leader.

New Brunswick MP John Williamson says he would like to have that job.

"I will respect my caucus colleagues. I will listen to our movement," he wrote on social media moments after O'Toole lost the vote.

"I know how to keep us united around the things that matter most to us as Conservatives."

The Reform Act, which has been in place since 2015, allows a party's MPs to trigger a leadership review instead of waiting for the question to be put to the wider membership.

The Conservative caucus is the only one that voted last year to accept the rule as binding.

The Canadian Press