Under fire over Mike Duffy, Harper clings to Conservative campaign message

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.

• Where the leaders are Monday
• Harper pledges expansion of military reserves
• Harper stands by chief of staff amid questions about Duffy scandal

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.

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.

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.

'Not a lie': Wright

Mulcairwas inNiagara Falls on Monday, where he notedthat inconsistencies withHarper's public comments are starting "to add up."

"Mr. Harper has not been truthful with Canadians, that has become abundantly clear from the emails that have been released and Canadians deserve better."

Trudeau was campaigninginAjax, Ont.where hewas askedabout aletter he wrote to Harper Sunday asking him to answer a list of questions he has refused to answer in public.

"Canadians... are very concerned with the fact that the PrimeMinister's Office and his senior staff were involved in a cover-up," Trudeau said. "The fact is these are very serious questions thatthe prime minister must answer."

Wright, the prime minister's former chief of staff, was in an Ottawa court again on Monday where he was cross-examined by Duffy's lawyer, Donald Bayne.

Duffy has pleaded not guilty to 31 charges of fraud, breach of trust and bribery related to expenses he claimed in 2013 as a senator and later repaid with money from Wright.

Before Wright gaveDuffy $90,000 to repay his ineligible expenses, there had been aninitial plan to see Duffy repay part of his expenses with money from the Conservative Partyfund.

But Wright testified he did not tell Harper about either plan.

Bayne asked Wright Mondaywhy he would lie to the prime minister.

"I don't think I lied to the prime minister," Wright said."I don'tfeel it was lie. Ijust felt it wasn't on my list of things Ineeded to check with him."