Fascinating.

Canada may be on the verge of a constitutional and political showdown, and the secessionist Bloc Quebecois is the kingmaker.

Prime Minister Stephen Harper, leading a conservative minority government, proposed to abolish government funding for political parties-- a move that would hurt his own part much less than the opposition parties, as the government subsidy makes up most of their budgets.

I've joked several times in this space about the apparent inability of Canadian parties to learn the word "coalition," but mortal threats concentrate the mind wonderfully, and the Liberal and NDP parties finally seemed to reach a willingness to join forces.

Problem: even combined, they have fewer MPs than the Tories. The balance of power is held by the Bloc, which has never entered into coalition or federal government since, after all, its raison d'etre is to free Quebec from the Canadian yoke.

Second problem: if the Tories lose a vote of confidence, the normal response is for the PM to ask the Governor General to dissolve Parliament and hold a new election-- but the last election was a matter of weeks ago.

So one question is: what does the GG do, if the PM is asking for a new election while Stephan Dion asks for the right to form a new government in the existing Parliament? And another question is: to grant Dion's request, what kind of participation would the GG demand from the Bloc? Passive support seems insufficient; active participation would be anathema both to the Bloc and to huge swaths of Liberal Anglophone Canada.

And it's worth noting just how topsy-turvy the world is in which the Bloc makes Stephane Dion Prime Minister. Dion has for two decades been one of the champions of Canadian unity and federalism within the Quebec debate, and has been a hate-figure for nationalists; Bernard Landry called him "le politicien le plus détesté de l'histoire du Québec." It would come as a serious surprise to me if either Bloc voters were happy that the Bloc installed Dion, or if Liberal voters were happy about any collaboration with the Bloc.

Harper has now backed down from the political party subsidy proposal. But the thing about political learning is that newly-learned lessons aren't quickly unlearned. The Liberals and NDP have finally learned, under mortal threat, that a coalition is thinkable-- and then they learned that they could terrify Harper, which they've proven unable to do for years. So they could still decide to vote no-confidence next week and bring the government down-- apparently throwing Canada's immediate political future into the hands of the GG, which is constitutionally unsettling in one way (Governors General, like the British monarch for whom they stand in, aren't really supposed to have political choices to make in our modern constitutional monarchies)-- and into the hands of the Bloc, which is constitutionally unsettling in another way.

A big week ahead. Fruits and votes is my recommendation for a blog on which to follow the action.