Trudeau says close to 300,000 Canadians are now members of the Liberal Party of Canada.
Back in April 2013, when Trudeau was elected leader, the party says membership stood at only 60,000.
However, more than twice that number had signed up for a newly created "supporter" designation, which allowed them to vote in the leadership race without becoming dues-paying, card-carrying members.
The latest membership numbers suggest that most supporters have since taken the next step of becoming full-fledged members, which entitles them to vote in nomination contests to choose the party's candidates for the next election.
Party insiders say most supporters have also become financial contributors.
Also on HuffPost