The attack ad producers for the Conservative party just received a late Christmas gift.

According to a story by the Sun News Network, NDP leadership frontrunner Thomas Mulcair holds dual Canadian and French citizenship and vows to keep both, even if he should one day become prime minister.

Mulcair was born in Canada but his wife, Catherine, hails from France.

Under French law, spouses of French citizens can apply, as Mulcair did, to become citizens themselves after five years of marriage and after demonstrating their ability to speak French.

"Mr. Mulcair is very proud to share the nationality of his wife, who shares his," Mulcair spokesperson Chantale Turgeon told Quebec's TVA.

"He sees no conflict with his Canadian citizenship or duties. Dual citizenship is a reality for many Canadians who are proud of their origins and a source of enrichment for our diverse society."

Will this news hurt Mulcair's campaign?

Not many Canadians seemed to care about the issue when former PM John Turner, who was born in England, was a dual citizen during his time in office.

But, in 2006, when it was learned that then Liberal leader Stéphane Dion held French nationality, it triggered a nation-wide rebuke.

At the time, several NDP MPs argued that a leader of a federal party should not have dual citizenship.

There's no doubt that Conservative spinners are salivating over these quotes that the Sun News Network's Brian Lilley dug up from 2006:

Jack Layton

"I would prefer that a leader of a party hold only Canadian citizenship,

because one represents many Canadians, and for me that means that it's

better to remain the citizen of one country," Layton told The Canadian

Press.

"But for a person that isn't in a position of representing others, holding

dual citizenship is fine with us."

Pat Martin

"Mr. Dion should not have divided loyalties," the Manitoba MP said.

"If he were ever to be the premier leader of Canada, this is going to be a

problem for him and he should not be so dismissive of people raising the

question."

Peter Stoffer

"I don't think it's good that a possible prime minister hold dual citizenship. Say you're the prime minister of Canada and you hold French citizenship … France comes knocking at your door for a deal … you're perceived to be in a conflict of interest. A prime minister should always be clear of any perception of conflict of interest."