Stephen Harper pounced on Stéphane Dion after an English-language interview in which he asked repeatedly for clarification on a question about the economy, saying it's a sign the Liberals don't have a plan.

"When you're running a trillion-and-a-half-dollar economy, you don't get a chance to have do-overs, over and over again," the Conservative leader told reporters covering his campaign tour in Winnipeg.

He said the incident clearly shows Dion has no plan for dealing with the global credit crisis that is threatening to spillover into Canada.

In the interview, CTV Atlantic anchor Steve Murphy asks Dion: "If you were prime minister now, what would you have done about the economy and this crisis that Mr. Harper has not done?"

Dion asks for clarification on whether he means winning the Oct. 14 vote or two years ago when Harper began his term. He then asks to start over and Murphy agrees. Several false starts later, the interview continues.

'A cheap shot': Liberals

CTV's Mike Duffy aired the clip Thursday evening for a panel of candidates running in the federal election, suggesting the gruelling campaign has taken a toll on Dion and questioning his English comprehension.

Liberal candidate Geoff Regan jumped to the defence of his leader, noting Dion's disclosure earlier in the campaign that he suffers from a hearing problem.

"That's clearly what happened here and I don't think we should spend a lot of time talking about someone's physical impairment," Regan says to Duffy.

Regan said he has worked with Dion in cabinet committees and Dion never had a problem understanding English.

Liberal Senator Jim Munson, a one-time spokesman for Jean Chrétien who is travelling with Dion on his campaign plane, dismissed the comments by Harper as a "cheap shot."

"The leader [Dion] has a slight hearing problem," said Munson. "He said that he didn't quite understand it. The interviewer agreed to stop and restart the tape."

With files from the Canadian Press