Bloc Québécois Leader Gilles Duceppe came to the defence of Liberal Leader Stéphane Dion on Friday over the Conservatives' lambasting of his performance during a recent English-language interview, saying francophone politicians are subjected to a "double standard" in Canadian politics.

When asked during a Quebec radio interview about the incident, an indignant Duceppe said many English-speaking politicians have little or no ability to speak French, yet francophones are somehow always expected to be perfect.

He accused Conservative Leader Stephen Harper of delivering a "low blow" by saying Dion's struggle to understand a question on the economy was a sign the Liberal leader is incapable of leading the country.

The Bloc leader said sometimes he has even preferred the English leaders' debate in past campaigns, because the poor quality of some leaders' French slowed the pace of the exchanges too much.

But Duceppe also took the opportunity to criticize Dion, suggesting he understood the question.

"The real question is that I think [Dion] understood the question. The real problem wasn't the language, it was the substance," Duceppe said. "He had nothing to say."

After several attempts by the CTV Atlantic interviewer to rephrase the question, Dion asked if they could restart the interview. The interviewer agreed, but the final footage that was aired included the earlier false starts.

'I've struggled with questions, too': Layton

Harper insisted the episode highlights greater concerns than language comprehension, and shows instead that Dion has no plan for dealing with the global credit crisis that is threatening to spill over into Canada.

But in an interview with CBC News on Friday, Dion portrayed the controversy over the interview as an attempt by Harper to divert attention from the Conservatives' election platform, which he called "a brochure." 

Asked for his opinion on the criticism, NDP Leader Jack Layton also defended Dion, saying he has "struggled with questions, too."

"I suppose if I were someone who could say I never had trouble with a question, I might be able to make some kind of a remark about it," Layton told reporters in Toronto. "But it has been a long campaign. People are tired, and questions are coming at you from sometimes even over your shoulder."

Layton said his problem with the Liberal leader was with his platform and his record of "propping up" Harper in the last Parliament.

"I have a big problem with that," he said.

Duceppe was also asked what he thought of Dion's overall ability to express himself in English.

"He does his best, he learned the language later [in life]," he replied.

With files from Tim Duboyce