The New Democrats are invoking Jack Layton's down-to-earth spirit in an advertisement introducing their new leader to Canadians.

Thomas Mulcair is painted as a crusader for ordinary Canadians in an English television advertisement released by the federal NDP on Tuesday.

Referring to himself as "Tom," Mulcair addresses viewers of the ad directly as he says "As a cabinet minister and as a member of Jack's team, I've always fought for you."

Much of the ad appears to focus on continuing the momentum the NDP experienced during the last federal election, as opposed to altering the party's core principles.

Change was a touchy subject during the party's seven-month leadership race, with NDP delegates torn between candidates who wanted to keep the party firmly on the left and others who supported a slight shift to the centre of the political spectrum.