OTTAWA - Opposition members are furious that the Tory government has rescinded an invitation for them to take part in the NATO leaders summit, where the future of Canada's Afghan mission will be decided.

The Liberal, New Democratic and Bloc Quebecois defence critics were invited to accompany Defence Minister Peter MacKay to the meeting in Bucharest, Romania, next week.

The Department of Defence sent out the invitations, but then revoked them on Wednesday, saying that NATO had limited the size of the Canadian delegation.

A spokesman for the military alliance has denied a cap on delegates has been set.

"The official Opposition has tried at every opportunity to work in a constructive fashion regarding our mission in Afghanistan, but once again we see from this government an unacceptable level of partisanship, going so far as to hide the facts from Canadians,'' said Liberal defence critic Denis Coderre.

He said the exclusion of opposition members flies in the face of the recent Manley commission report, which called on the Tory government to be more open and accountable when it comes to the mission in Afghanistan.

Prime Minister Stephen Harper will lead the Canadian delegation at the meeting, to take place April 2-4.

MacKay, Foreign Affairs Minister Maxime Bernier and Chief of Defence Staff Gen. Rick Hillier will travel separately to Romania.

NATO leaders are expected to discuss Canada's demand for 1,000 reinforcements.

The French have signalled they're ready to send more troops to Afghanistan, but are expected to deploy them to the eastern portion of the country, where they will free up American soldiers to fight alongside Canadians in Kandahar.

Parliament recently passed a motion to extend Canada's military mission, as long as NATO provided reinforcements and National Defence acquired battlefield helicopters and unmanned surveillance planes.

"This is a government that said the motion to extend our mission wasn't a Conservative motion, it wasn't a Liberal motion, it was a Canadian motion,'' said Coderre. "So why has this become a Conservative trip, and not a Canadian trip?''

A spokeswoman for Harper insisted the delegation is a government one and not open to opposition members.

Sandra Buckler said there are some international meetings when opposition critics are "paired'' with government minister, but this isn't one of them, even though invitations were issued.

"I absolutely can't explain what happened with that, but I can tell you that this is a government delegation and that on this trip there will be no pairing,'' she said Thursday.

Opposition members have complained regularly about being restricted by the Tories when it comes to trips involving Afghanistan.

In the winter of 2007, former defence minister Gordon O'Connor wouldn't allow members of the all-party Commons defence committee to travel away from Kandahar Airfield during a fact-finding mission.

Coderre travelled to Afghanistan on his own last year after being denied permission to visit Canadian troops serving in Kandahar.