Justin Trudeau's campaign has released a total number of potential voters for him in the "supporter" category that likely exceeds the efforts of any of the other seven candidates in the Liberal leadership vote.

Trudeau's campaign office says it has signed up 150,000 supporters, either on Trudeau's own website or by Trudeau personally, one supporter at a time. A goal was to have Trudeau meet a thousand people a day, spread over eight or nine events held daily. His team, equipped with iPads, would follow the easily recognized candidate and sign up supporters in his wake, or they would collect paper forms people signed on meeting Trudeau, and enter the data later.

The release of the numbers Sunday, as the deadline passed for any more supporters to sign up, was a muscle-flexing gesture by the Trudeau team, and perhaps a signal the other candidates should have a frank conversation with themselves.

But another candidate, MP Joyce Murray, said in a scrum outside the House of Commons today her supporters number in the "tens of thousands" and that there is no way to verify Trudeau's figure.

None of the other candidates have released numbers of supporters, and it's possible many don't know how many supporters might be inclined to vote for them, since most candidates couldn't match Trudeau's ability to drive supporters to his own website, justin.ca, rather than the Liberal Party site.

Supporters are a special category designed by the party to open up the race beyond the party membership. Supporters can sign up to vote in the Liberal leadership race without agreeing to join the party and without paying a fee as long as they are 18 or over and not a member of any other political party.

It's this unique combination of ease of sign-up and a very wide net that dovetails with the machine-like Trudeau organization. His campaign office says an army of 10,000 volunteers has been working on signing up supporters, and the same group will now start to make sure those supporters register to vote and then actually vote during the week between April 7 and April 14.

'The game changer'

The fact that so many volunteers came forward was "the game changer," a spokesperson for Trudeau's team said.

Trudeau's campaign office said it doesn't have a riding-by-riding breakdown of the 150,000 supporters, an important figure since every riding has a 100-point weight. Supporters concentrated in the big cities aren't the boost that supporters spread evenly across the country will be.

Supporters and all voters in the leadership contest will vote in a one-time preferential ballot, and no matter who signed them up, they're free to pick any candidate as their first choice.

Although supporters must be 18, party members who belong to Young Liberals of Canada can vote in the leadership by age 14, a factor that might pay off for Trudeau who spent years doing speaking engagements in schools.

Trudeau's biggest challenge may be in ensuring his supporters actually get around to casting their ballots, considering research in election after election shows that young people in particular don't vote, even though they have indicated that they intend to vote for a favoured candidate.

The Liberal party had promised that it would reveal the total number of supporters Monday, allowing anyone to do the math and compare Trudeau's numbers with numbers from the rest of the candidates combined, as well the supporters garnered by the liberal.ca website. But in a tweet, Mike Crawley, the party's president, said there was a "huge diverse pre-cutoff surge of supporters" that exceeded expectations and a couple of days would be needed to "scrub" the list.

In an email, a spokesperson for the Liberal Party wrote, "There are some estimates that people have made with numbers that are out there, but our priority is reporting on a final number, expected mid week. And most importantly, between now and March 14, we are going through a big push to encourage these eligible voters to become registered voters."