Prime Minister Stephen Harper tried Tuesday to draw Liberal Leader Stéphane Dion into the controversy over Green party Leader Elizabeth May's comments comparing the government's approach to climate change to Britain's appeasement of the Nazis.

May, who has been studying to become an Anglican minister, told an Ontario church congregation on the weekend that addressing climate change is a "moral obligation" and that Harper's stand on the issue was "a grievance worse than Neville Chamberlain's appeasement of the Nazis."

During question period in the Commons Tuesday, Harper noted that May's remarks have drawn criticism from the Canadian Jewish Congress, and also referred to her as Dion's "colleague."

Dion and May recently agreed not to run candidates in each other's riding during the next federal election.

"The leader of the Opposition hitched his wagon to this individual," Harper said. "I hope he will distance himself from those kinds of remarks."

When Dion declined to respond, Harper persisted, saying: "I think the leader of the Opposition should be able to say that he believes diminishing the Holocaust and using Nazi analogies are inappropriate, so I'd like to again give him the chance to distance himself from these remarks by his colleague, the leader of the Green party."

However, Dion ignored the remarks, sticking instead to his opening line of questioning relating to alleged abuse of prisoners in Afghanistan.

May should withdraw comment, Dion says

Later outside the Commons, Dion said May should withdraw the comment, even though references to weak-kneed Chamberlain are often used in commentary on environmental or poverty issues.

"We should not use it — for the very reason that in the spectrum of power, the Nazi regime is beyond any comparison," he said.

Dion said that while climate change poses a global threat on the same scale as terrorism and nuclear proliferation, and is indeed worrying, "you don't need to go over the top."

On Monday, May defended her controversial comments, telling the National Post that she had borrowed the quote from British author George Monbiot, who made a weekend appearance with environmentalist David Suzuki.

She said the quote was an example of how the federal Conservatives are tarnishing Canada's reputation around the world.

In the buildup to the Second World War, Chamberlain — then the British prime minister — adopted a policy of appeasement toward Nazi Germany.

May spoke on Sunday to the congregation of the Wesley Knox United Church in London, Ont., at the invitation of Liberal MP Glen Pearson, who defeated her in a federal byelection in the riding last November.