OTTAWA -- The NDP and Liberals have been shut out of the delegation that will accompany Foreign Affairs Minister John Baird to Kyiv on Friday, sparking fresh criticism that the government is playing domestic politics with an international crisis.

Four prominent Ukrainian Canadians will join two Tory MPs and a Conservative senator with Baird. But there are no opposition MPs in the group.

The NDP and Liberals said they asked the government if they could be represented but were turned down. The Conservatives, meanwhile, were making no apologies for that.

Jason MacDonald, the chief spokesman for Prime Minister Stephen Harper, said that neither opposition party was worthy of inclusion on the trip because of past behaviour.

He cited the flippant joke that Liberal Leader Justin Trudeau made on a Quebec television show about the crisis (Trudeau apologized Tuesday to the Ukrainian ambassador) and the NDP's past criticism of Baird's foray into Kyiv's main square in support of protesters in December.

"Mr. Trudeau's comments about Russia and Ukraine were neither helpful nor did they contribute positively to Canada's efforts to assist the Ukrainian people, and as a result there's no role for the Liberals in this government mission," MacDonald said Wednesday in an email to The Canadian Press.

"The NDP wouldn't pick a side, unlike our government, which has been steadfast in its support for the Ukrainian people. Until they decide on what they stand for they, like the Liberals, shouldn't be a part of the government delegation."

Earlier this week, NDP foreign affairs critic Paul Dewar sent a letter to Baird asking for an all-party delegation to the Ukraine.

"Canadian parliamentarians of all parties should work together to show that our friendship with the Ukrainian people is a long-term commitment," Dewar wrote.

When he learned the make-up of the delegation, Dewar tweeted, "Glad for Canadian delegation to #Ukraine as NDP requested. Too bad only MPs from one party. We all stand with Ukrainian people."

The Liberal foreign affairs critic Marc Garneau said he sent an email to Baird asking to participate but received no reply.

"This is not a way to communicate to Ukraine what multi-party democracies are like, because the reality is that all of the main parties share the same concerns about Ukraine," Garneau said in an interview.

Garneau said he wasn't surprised by the government's decision.

"This would have been a good opportunity for the government to show that it rises above partisanship."

Trudeau said Wednesday he was disappointed at the latest example of the government "using foreign affairs for domestic political advancement."

"Canadians are united in their support of Ukraine," he said.

"All of us represent Ukrainians in various ridings."

NDP Leader Tom Mulcair sidestepped a question on the make-up of the delegation.

"Frankly, at this stage of the game, I simply wish them success. I hope that it works," he said.

Parliament was to hold a non-binding, take-note debate Wednesday evening over the crisis.

The government, which has sent monitors to Ukraine in the past, is expected to use the debate outline its support of the country's next steps toward democratic elections.