Foreign Affairs Minister Lawrence Cannon said the last-minute G8 guests will add a lot to the discussion around the table when leaders meet June 25-27 in Huntsville, Ont. (Canadian Press)

The G8 Summit in southern Ontario's cottage country will include 10 other countries, and that has invited concerns and criticisms from politicians and activists.

The G8 consists of eight of the world's leading economic powers, including Canada, the United States and the United Kingdom. This year's annual summit will take place June 25-27 in Huntsville, Ont., but officials said it will also include leaders from Haiti, Jamaica, Colombia and seven African countries.

"And what is all this costing?," asked Liberal MP Siobhan Coady, during the House of Common's question period. "There's no limit to what Canadians will have to pay for the prime minister's ego."

NDP MP Paul Dewar said aid-recipients Haiti, Jamaica and Colombia recently signed a free-trade agreement with Canada and their leaders likely won't disagree with Prime Minister Stephen Harper.

"Is this really a meeting of the G8 or is this, in fact, just a meeting of the campus of conservative club, Mr. Speaker?" he asked during question period.

Foreign Affairs Minister Lawrence Cannon said the last-minute G8 guests will add a lot to the discussion around the table.

"The prime minister will be discussing issues that are related to development," he said. "He will be discussing issues related to security, global security, Mr. Speaker."

But NGOs say the government shouldn't limit the discussion to only those topics.

"For Canada to invite those people and not talk about climate change, not put it on the agenda and make sure there is very strong commitment, would be highly hypocritical, and, frankly, if I was from an African country, I'd be outraged," said Steven Guilbeault, co-founder of the environmental group, Équiterre, in Montreal.

Zoë Caron, a climate policy and advocacy specialist at WWF-Canada, said developed countries agreed last December in Copenhagen to help developing nations cope with climate change by putting money into a fund, but so far there isn't much in it.

"I think that having those faces at the table and those voices at the table would very much support those dollars moving forward," she said.

Cannon said climate change is on the agenda, but environmental groups worry it will get only a passing mention, instead of a full discussion about what needs to be done to reach an international agreement by the end of the year.