Harper again grilled about Duffy trial while campaigning in New Brunswick

WATCH ABOVE: Conservative Leader Stephen Harper can’t seem to get away from the Mike Duffy trial during his federal election campaign stops, including the one in Fredericton, N.B. on Monday. Jacques Bourbeau reports.

OTTAWA – Questioned relentlessly at every campaign stop about the fallout from the Mike Duffy trial, Stephen Harper is refusing to be knocked off his double-barrelled core campaign message: economy and security.

The Conservative leader is stressing the latter at a stop in Fredericton, N.B., where he is promising to add 6,000 people to bolster the reserve ranks of the Canadian Forces reserves.

Harper says the measure will cost $163 million over three years and $63.4 million going forward once the overall target of 30,000 personnel is reached.

WATCH: Prime Minister Stephen Harper asked about key members of his team knowing about the $90,000 cheque to Mike Duffy.

His main opponents, meanwhile, want heads to roll over the Duffy affair. Liberal Leader Justin Trudeau wants staffers in the Prime Minister’s Office fired; NDP Leader Tom Mulcair says it’s Harper who should be turfed.

Story continues below advertisement

WATCH: Stephen Harper again refused to admit any involvement over Nigel Wright’s involvement in the Mike Duffy senate scandal.

But the prime minister says the two people to blame are Duffy and Nigel Wright, Harper’s former chief of staff, the star witness at Duffy’s trial and the man who personally paid the embattled senator’s questioned expenses.

Harper – ignoring evidence that indicates a number of PMO staffers were aware of the arrangement – says Duffy and Wright were the two principal players and are the ones being held accountable.