OTTAWA - Opposition critics are accusing Stephen Harper of an about-face on the Afghan mission, noting that the prime minister who once dismissed them as defeatists now acknowledges western forces alone can never beat the Taliban insurgency.

Liberal, NDP and Bloc Quebecois MPs said Harper's remarks, broadcast Sunday on CNN, are in sharp contrast to his previous assertion that Canada would never "cut and run" in Afghanistan.

Harper told the U.S. television network that the Afghan government needs to be able to manage the persistent Taliban insurgency that rages across swaths of the country.

"We're not going to win this war just by staying," Harper said.

"Quite frankly, we are not going to ever defeat the insurgency. Afghanistan has probably had - my reading of Afghanistan history (is) it's probably had an insurgency forever of some kind.

"What has to happen in Afghanistan is we have to have an Afghan government that is capable of managing that insurgency."

Opposition MPs attacked Harper in the House of Commons on Monday for what they claim is a 180-degree turn on the Afghan mission.

"By the way, Mr. Speaker, remember 'cut and run'? Remember 'we're not going to leave until the job's done'? What's going on, Mr. Speaker?" said NDP MP Paul Dewar.

Dewar was referring to remarks Harper made on a March 2006 visit to Afghanistan, amid a spike in Canadian war casualties, when the prime minister told soldiers Canada wouldn't turn tail when the going got tough.

"There will be some who want to cut and run, but cutting and running is not my way and it's not the Canadian way," he said at the time.

The Conservatives have maintained for some time that building up Afghanistan's fledgling security forces to the point where they can keep the Taliban at bay is the Canadian military's end game in Afghanistan.

However, following last year's report by former Liberal deputy prime minister John Manley and his blue-ribbon panel of experts, the Tories also began emphasizing reconstruction and development as equally important pillars of the Afghan mission.

But opposition MPs say Harper's comments on CNN are a departure from his previous remarks.

"I think to state categorically that we're not going to defeat the insurgency, and then not to say what the rest of strategy is as a result of that determination, is frankly a little strange," said Liberal MP Bob Rae.

The Conservatives, however, say Harper's comments to CNN are in line with the government's position in Afghanistan.

Tory MP Laurie Hawn, parliamentary secretary to the defence minister, said Harper didn't say anything he hasn't said before.

"Mr. Speaker, the prime minister and anybody who is knowledgeable about the mission has been saying from the start that this is not a militarily winnable mission alone," Hawn said.

"The simple fact is, Mr. Speaker, our priorities haven't changed, our methods haven't changed. The prime minister was talking about military-alone solutions, and nobody has ever said that is the ultimate solution."

During last fall's federal election, Harper scoffed at the notion that coalition forces could wipe out the insurgency in a short period of time.

"The idea that we would just eradicate it in a few short years is just unrealistic," he said at the time.

The opposition parties questioned whether Harper is leaving the door open to another extension of the Afghan mission beyond the 2011 pullout date.

Parliament agreed last year to extend the military mission in volatile Kandahar province to 2011 beyond the initial 2009 end date.

Some 2,750 Canadian soldiers are deployed to Kandahar province, a beachhead in the bloody battle against a stubborn Taliban insurgency. Canada's death toll stands at 108 since the Afghan mission began in 2002.

Harper declared in the early days of last fall's federal election that Canada's military commitment in Afghanistan will end in 2011 as scheduled, and that the Afghan government "at some point has to be able to be primarily responsible" for the country's security.