Rosemont-La Petite-Patrie MP Alexandre Boulerice announced Wednesday he will support Topp's effort to take over the helm of the NDP. He is considered a rising star in the New Democrat caucus.

Quebec MP and NDP House Leader Thomas Mulcair is expected to join the race in Montreal next week.

The party will name Jack Layton's successor at a leadership convention in Toronto in March.

Topp now has the support of other NDP caucus members including deputy leader Libby Davies and labour critic Yvon Godin. He also is endorsed by party heavyweights including former party leader Ed Broadbent and former Saskatchewan premier Roy Romanow.

Other NDP leadership contenders include MPs Paul Dewar, Nathan Cullen and Romeo Saganash.

NDP finance critic Peggy Nash has indicated she may throw her name into the competition following the Ontario provincial election on Oct.6.