There are a number of ways a federal election could be triggered this week.
The governing Conservatives may well prefer to be brought down on a budget issue, which would make a better campaign message for them, than on a no-confidence motion from the opposition highlighting matters of integrity and accountability.
Here are the possible ways that the government could fall:
The Commons was asked on Monday to find the government of Stephen Harper in contempt of Parliament for failing to provide all of the information requested by opposition MPs around the cost of the Conservative crime legislation and the purchase of 65 stealth fighter-bombers.
That issue will be debated Wednesday and could be voted on Thursday. But the government, which is in charge of the parliamentary calendar, could delay a vote until next week. And although finding the government in contempt would be historic, and would certainly make it difficult for the Conservatives to carry on, a contempt vote is not necessarily a confidence motion. So this is highly unlikely to be the issue that leads to an election.
2. Amendments to the budget
Before the end of the day on Wednesday, the Liberals will table an amendment to the budget, and the Bloc will table a sub-amendment. Both could be considered confidence votes.
The Liberal amendment will not be put to a vote until next week, which means the Bloc sub-amendment could well become the flint that sparks the election. That sub-amendment is expected to centre on the Quebec government's call for a $2.2-billion sales-tax harmonization deal with Ottawa, similar to existing agreements in Ontario and British Columbia. The sub-amendment could be put to a vote on Thursday, but, as with the contempt motion, the government could put it off until next week.
3. A motion of no-confidence
Although the government controls the parliamentary calendar, it cannot delay a Liberal opposition day, which has been scheduled for Friday. Nor can it put off the two other supply bills that must follow the Liberal motion and are also considered matters of confidence. The Liberal motion will be tabled in the House of Commons on Wednesday, and that is when the government will learn what it is up against.
Liberal Leader Michael Ignatieff was coy when asked after the budget was tabled whether the Liberal motion would express a lack of confidence in the government. "We take the issue of contempt of Parliament and disrespect for our institutions very, very seriously," he replied. "What I want to do today is focus on the budget judgment. We've got a caucus meeting tomorrow and we'll make a decision then and you'll know by early tomorrow afternoon."
4. A vote on the budget
Even if the opposition voted for a Liberal motion of no-confidence, it is the government that decides what is actually confidence and what is not. So, if the opposition members say they have lost the confidence of the House, the government could choose not to accept that decision.
But, if that happens, the Conservatives would still face votes on the budget next week which would be matters of confidence and, ultimately, it would be impossible for the government to carry on. As one New Democrat said Tuesday: "They can run but they can't hide."
With a report from Daniel Leblanc