A federal budget is being finalized. Another election window is upon us. What’s going to happen?

Anything can happen in politics. But it is often possible to predict the behavior of political actors by trying to understand their interests. What are the interests at play this spring?

Begin with the chessboard. Given equally-competent campaigns, it seems true that leader numbers (measured in different ways but amounting to “do you want that leader in your living room for the next four years?”) and party vote numbers often converge by the end of a campaign.

So, with about 35 per cent of Canadians saying they like Stephen Harper and about 35 per cent saying they intend to vote for his party, it looks like 35 per cent or so is what Mr. Harper could hope to get in an election.

Jack Layton also enjoys about 35 per cent leadership support. His party polls around 17 per cent these days. So it could be said that Mr. Layton has some headroom in a campaign.

Michael Ignatieff polls perhaps 15 per cent as a leader. His party around 27 per cent or so. And so the Liberals might have further to fall, unless Mr. Ignatieff’s strangely contradictory “Only I Can Prevent the Harper Policies That I Support” campaign catches fire among New Democratic and Conservative voters who don’t like him.

(Mr. Duceppe’s Bloc is a special case. With a perfect split among their opponents, a popular leader and a seemingly solid vote, they are the federal political players in the least-ambiguous position. They are on the hunt against a collection of vulnerable Quebec Tories who will be running a series of by-elections to try to survive, while the Conservatives conduct a classic “vote for the government to get some goodies” campaign. Wasn’t that the basic message of Duplessis?).

Is there more to it? The Conservatives balance two big interests.

In favour of avoiding an election: their single best asset is the fact that Mr. Harper is the Prime-Minister-in-residence and nothing vote-determinedly bad has happened so far. Thus, possibly, the longer Mr. Harper is Prime Minister, the better his appeal. The economy is on the mend. The government has two more years in its mandate. What’s not to like about continuing to govern?

In favour of going now: the Conservatives have an overwhelming financial advantage over their opponents. And there is an important risk that Mr. Ignatieff might be fixed or replaced if there isn’t an election this spring.

The bottom line: Since their interests seem finely balanced, it seems safe to predict that the Conservatives will not be flexible or generous negotiators with potential opposition partners around this budget. They will stick to their “take it or leave it” style; toss a few crumbs to maintain their pose as focused on governing. And see if the Liberals or the New Democrats blink. Either outcome — another year in office or an election — probably works for them.

The NDP is on the same dime it’s been on since 2004.

In favour of avoiding an election: New Democrats like minority parliaments, and so in principle aren’t eager for constant elections that suggest minority parliaments can’t work. More important: Mr. Layton is sincere when he says he’s in Parliament to get things done, as he has repeatedly demonstrated. So if there were a truly compelling public policy case for keeping Parliament going, Mr. Layton might do so. In the spring of 2005 it was the “NDP budget,” which temporarily redirected foolish Liberal corporate tax cuts to productive investment in public transit, housing and many other good things. In the fall of 2009 it was employment insurance reform. In the spring of 2011? Mr. Layton has been clear about what’s on his party’s mind.

In favour of going now: While Mr. Layton has been a good partner to both Liberal and Conservative minority governments when they were interested in that partnership, he has always been clear that his party’s support isn’t and cannot be available for free. The New Democratic base likes to see important things getting done — as do most Canadians. But NDP voters and leaners are intolerant of open-ended, unconditional support for governments they don’t like — in particular, Conservative governments they don’t like. So unless a compelling public policy case exists to preserve the Harper government, then the political case against doing so likely takes precedence.

The bottom line: unless the Prime Minister magically morphs into Senator Hugh Segal (who was offering the Tories some good advice last week) in the next two weeks or so, it seems hard to see how there will be a meeting of the minds around the next budget between Mr. Harper and Mr. Layton.

That leaves Mr. Ignatieff’s team.

In favour of avoiding an election: Mr. Ignatieff is a year into his latest new look, having fired his closest associates (or lost them to the Tories) and put himself into the hands of saviours who learned their tricks and gadgets during a different political era. The declining minority of Liberal-friendly media swooned. But nothing else has improved — arguably, on some metrics, the Liberals are in worse shape now than they were a year ago. So buying another year might be the right thing to do, perhaps to finally fix Mr. Ignatieff, or to replace him.

In favour of going now: It could be argued that when the poker game you’re in is not working for you, it’s time to find a different one. Mr. Ignatieff is not thriving. Perhaps a new environment — like an election campaign — will get him a reset with the public, a second look, and a chance to turn things around. If so, perhaps things would improve for the red team. If not, at least Mr. Ignatieff and his faction would be liberated. Mr. Ignatieff could return to Harvard. His advisers could go back to Bay Street to the pay they’ve become used to. And somebody else could worry about what happens next. Liberals are calling this “clearing the air.” “Let’s get this over with” is more like it — never a compelling campaign slogan, but perhaps the best Mr. Ignatieff can do in current circumstances.

The bottom line: the Liberal faction currently driving that party wants an election now to either reverse its fortunes or retire.

So: Mr. Harper will take or leave an election. But is in no mood to negotiate, just like always.

Mr. Layton will take or leave an election. But he requires a real advance in public policy — not apparently on offer — just like always.

Mr. Ignatieff wants an election. The glittering trappings of office — or the villa in the south of France — beckon.

My bet is therefore that there’s going to be an election this spring, in early to mid-May.