Final membership numbers released Tuesday by the party show membership has swelled to 128,351, an increase of just over 50 per cent since the start of the leadership contest last October.
All members are entitled to cast ballots, starting March 1 and culminating in a leadership convention on March 24.
British Columbia, with 38,735 members, and Ontario, with 36,760, will have the most influence over which of the seven contenders emerges victorious. The two provinces account for 30 per cent and 28.6 per cent of the membership respectively.
Ontario outstripped all other provinces in terms of membership growth, adding more than 14,000 members since October.
In Quebec, membership numbers have shot up to 12,266 from an almost non-existent 1,695 last fall. That represents a 600 per cent increase.
Still, Quebec accounts for only 9.5 per cent of the total membership, leaving the province with limited influence in choosing the party's next leader even though it delivered more than half the 103 seats won by the NDP in the May 2 federal election.
Montreal MP Thomas Mulcair, considered the front-runner, is likely the prime beneficiary of the Quebec growth spurt. However, the numbers are well short of the 20,000 members his camp had hoped to recruit in the province.
"You have to set yourself ambitious targets to get good results and the results are historic," said Mulcair campaign director Raoul Gebert. "The NDP has never had these many members in Quebec at all and we started with very, very low numbers."
Gebert maintained the "overwhelming majority" of new Quebec members are supporting Mulcair, whom he said has also amassed "good support across the country from coast to coast."
Quebec's clout is virtually identical to Manitoba's 12,056 members (9.3 per cent), and only slightly better than Saskatchewan's 11,264 (8.7 per cent), and Alberta's 10,249 (7.9 per cent).
Nova Scotia is the most influential of the Atlantic provinces, with 3,844 members (2.9 per cent). The other three Atlantic provinces and the northern territories each account for less than one per cent of the national total.
It's impossible to accurately measure support for each of the seven leadership hopefuls. But the regional distribution of the membership numbers do provide some clues as to how each camp is faring.
The B.C. numbers are especially encouraging to former party president Brian Topp, who has amassed a formidable organization and impressive roster of endorsements from party luminaries in the province, including deputy leader Libby Davies.
"The B.C. numbers are eye-popping," said Topp campaign director Raymond Guardia.
He also maintained the Topp camp "got more than our share of the Ontario increase" and "out-recruited Mulcair in Quebec since January."
Nathan Cullen, a B.C. MP, also claims strength in his home province.
Ontario is more of a mixed bag, with Toronto MP Peggy Nash, Ottawa MP Paul Dewar, Mulcair and Topp all claiming significant support.
Nash's camp said it signed up "a significant portion" of the new members nationally and took particular encouragement in the Ontario growth spurt.
"It's also very good news that the Ontario numbers are as high as they are since Peggy has such high first- and second-ballot support there," said Nash campaign director Riccardo Filippone.
Dewar's team said the numbers are "very positive" for the Ottawa MP, who has built a strong ground campaign in Manitoba, Alberta and parts of Ontario.
"The numbers reinforce that Paul Dewar has a clear and strong path to victory," said spokesman Joe Cressy.
Cullen got a potential big boost from two online advocacy groups, which launched membership drives last week. Both groups are promoting the idea of co-operation among progressive parties to defeat Prime Minister Stephen Harper's Conservatives — an idea Cullen has embraced.
"We are very confident Nathan was an attracting force for many new members," said campaign director Jamey Heath, adding that more than 800 members joined the party through Cullen's website last week alone.
The other contenders are Churchill MP Niki Ashton, who has bases of support in her home province of Manitoba and in Saskatchewan, and Nova Scotia pharmacist Martin Singh, who has signed up more than 4,000 members, particularly among Sikh communities in the Toronto and Vancouver areas.
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