A vote sign is displayed outside a polling station during advanced voting in the Ontario provincial election in Carleton Place, Ont., on May 24, 2022. (The Canadian Press/Sean Kilpatrick)
The preliminary figures are more than double the number of members leadership hopefuls wrangled in the 2020 leadership race, when the party broke the record for most sign-ups with 270,000.
There are still several steps remaining to certify the membership applications and leadership race chair Ian Brodie says the final number of eligible voters is likely to change.
Some campaigns and party insiders have expressed serious concern about the party’s ability to process the memberships and get ballots out in time to ensure a fair race.
The party says it has been able to scale up operations to manage the increased membership numbers and ballot packages are expected to be sent to all eligible voters in late July and early August.
Completed ballots must be received in Ottawa no later than Sept. 6.
The party will not confirm the number of memberships signed up by individual campaigns.