OTTAWA - Veteran MP and deputy leader Libby Davies is backing party president Brian Topp in the race to succeed the late Jack Layton as NDP leader.

Davies' announcement came today, just hours before fellow British Columbia MP Nathan Cullen was expected to declare his candidacy for the job.

Topp, a fluently bilingual Quebec native, has racked up some heavyweight backers since he became the first to enter the race after Layton died from cancer in August.

He's since been challenged by Romeo Saganash, a former Cree leader and first-time MP from northern Quebec.

Ottawa MP Paul Dewar is expected to declare his candidacy on Sunday.

Other potential candidates include Nova Scotia businessman Martin Singh, along with MPs Thomas Mulcair, Niki Ashton, Peter Julian and Robert Chisholm.

Davies opted out of running Sept. 22.

The NDP leadership convention will be held March 24 in Toronto.