This Liberal-NDP-Bloc coalition is illegitimate. It's not illegal, which is a different concept. It has no legitimacy for several reasons:
There are other reasons too, but for now, we can move on.
If this coalition is allowed to seize power and avoid testing their still unknown platform in an election, then Canadians will have no idea what to expect for the next two years (I doubt it will last that long, but that's their plan).
Indeed, whatever direction is set for the first six months won't survive the change in leadership in May. On the positive side, the coalition is not likely to survive that change in leadership either, but there is a lot riding on that bit of optimistic thinking.
The prime minister can prorogue the House. He should. Will he take a political hit for this? Yes. In fact, given the mess that has to be cleaned up, Stephen Harper could consider proroguing the House and then setting up a leadership review for the near future -- essentially promising that an accounting will happen.
But the important thing is to move the calendar forward to late January. Barack Obama will be installed as President, and the outlines of the US plans going forward will be made known. Then Jim Flaherty can design a budget that makes sense (which was always his plan).
At that point, with a rational economic package in place, the House can decide on whether to proceed.
The opposition might move forward on the plans for this coup regardless. Fair enough. But for that to happen, they will have had to maintain this agreement in the intervening weeks, and in the face of an economic stimulus package presented by the government.
They would also have to admit that the reason behind this coup has nothing to do with budgets and stimulus packages, and that they are simply committed to ignoring the results of an election that they lost.
If they have the stomach to be openly honest about their true motivations, then at least there is a hint that the plotters could keep this thing running for more than a few weeks. If they can admit that this is just about power and nothing else, then having power might be enough to keep the coalition tied together. Then the Governor General can decide if that is a government Canadians deserve to have.
But if they can't hold it together once the true reason for this coalition is clearly exposed, then Canada would have dodged a big bullet by letting this coalition fall apart on the opposition benches.
Prorogue the House. See if these guys can sustain a single coalition party in opposition, without the perks of power, at least for just a short while. Force them to admit that nothing is going to keep them from overthrowing out the results of the last election, because overthrowing those results is the sole reason for this coalition in the first place.