The latest candidate financial reports filed with Elections Canada show the Montreal MP had raked in just over $205,000 from 1,347 donors by the end of February.
The numbers suggest Mulcair is the candidate with momentum; his haul is up $60,000 since the end of December.
Former party president Brian Topp isn't far behind, with $183,000 from 984 donors.
Topp had been the leading fundraiser up to the end of last year but he's raised only about $14,000 since then.
Ottawa MP Paul Dewar has also showed momentum, collecting $144,000 from 782 donors, up about $50,000 since December and now ahead of Toronto MP Peggy Nash in the fundraising stakes.
Nash has gathered $139,000 from 727 contributors, up $31,000.
The three other contenders — Nathan Cullen, Niki Ashton and Martin Singh — have not yet submitted their reports, which are due Saturday.
The reports show the financial status of each candidate's campaign from the time of registering as a candidate last fall until the end of February.
Of the four who've submitted reports so far, Topp is the only one who records taking out a loan — $100,000 from John Sterling a friend who "made a personal loan to help get the campaign off the ground," according to a Topp spokesman.
Topp also reports a $20,000 line of credit; Mulcair $15,000 and Dewar almost $31,000.
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