OTTAWA -- Ignore it and maybe it will go away.

That appears to be Stephen Harper's plan for the Senate -- at least in the short term.

The prime minister distanced himself from the damning revelations in last week's audit of senators' expenses, explaining that "the Senate is an independent body and the Senate is responsible for its own expenses."

He threw in the towel on his three-decade campaign for an elected Senate last year after the Supreme Court advised he'd need a constitutional amendment approved by most or all provinces to reform or abolish the upper house -- advice Harper paraphrased as "we're essentially stuck with the status quo for the time being."

He stopped appointing senators a year earlier, just as the expenses scandal was engulfing his government. There are now 20 vacancies in the 105-seat chamber and there'll be two more to fill by mid-summer.

And yet, according to the Prime Minister's Office, "We have no plans to appoint senators. The Senate continues to pass government legislation."

With an election looming in just four months, former allies in the Senate reform movement are mystified by Harper's strategy, or lack thereof.

"I'm quite puzzled actually how poorly this file has been managed by the prime minister," says political scientist Roger Gibbins, former head of the Canada West Foundation.

"I mean, this is kind of his issue and yet he's got himself in a very difficult situation."

The Supreme Court ruled that the Senate can't be abolished by stealth, so allowing its membership to dwindle indefinitely is not tenable over the long term. A Vancouver lawyer is already asking the Federal Court to declare that vacancies must be filled within "a reasonable time" and Gibbins suspects that, eventually, some provinces will also go to court to demand their full share of Senate representation.

Hence, as Gibbins sees it, Harper has painted himself into a corner and now faces two unpalatable options: He can make a raft of Senate appointments before the election, a scenario bound to trigger a public backlash at any time but which would amount to political suicide in the current climate.

Or he can wait and risk leaving the vacancies for another prime minister to fill should the Conservatives lose the election. That would be a "gift-wrapped package" for Liberal Leader Justin Trudeau, who's promising to create a blue-chip advisory body to recommend non-partisan nominees for Senate appointment, and a poisoned chalice for NDP Leader Tom Mulcair, who's vowing to launch constitutional negotiations to abolish the chamber altogether.

But either way, if Harper loses control of the House of Commons, he'd be ceding the Conservatives' domination of the Senate as well, an outcome for which Gibbins doubts "his party would ever forgive him."

Political scientist Tom Flanagan, a former Harper campaign manager, doubts the prime minister is giving much, if any thought, to what-if scenarios.

"Knowing him as I do, I don't think he's too much concerned about what the situation would be if he was no longer prime minister ... I think he'd be focussed on winning the election."

And on that score, Flanagan says it appears Harper is determined to ride out the Senate storm by keeping the appointment of senators off the table until after the election.

Trouble is, the more the vacancies pile up, the more insistent the questions become about how Harper intends to fill them, whenever that might be.

Both Gibbins and Flanagan think Harper may eventually adopt some variation of Trudeau's proposal. But having heaped ridicule on Trudeau -- calling his proposal a recipe for having Liberal hacks recommend more Liberal hacks for Senate appointments -- Flanagan says that would be difficult for Harper to admit to before the votes are counted on Oct. 19.

In any event, in the immediate aftermath of the Senate expenses audit and in the hyper-partisan, pre-election climate, Gibbins reckons it would be well-nigh impossible to persuade non-partisan, pre-eminent people to accept Senate appointments.

Alternatively, Gibbins suggests Harper could promise to hold a national plebiscite on abolishing the Senate, hoping public outrage would put pressure on recalcitrant provinces, including Quebec and Ontario, to go along with the initiative.

With or without a plebiscite, however, abolition is not something that could be accomplished over night, if ever. And Harper would still face the question of what to do in the meantime with the steadily increasing number of empty seats -- at least 34 by the end of 2017, fully one-third of the Senate seats -- as would Mulcair.

Whatever Harper is contemplating, Flanagan is sure of one thing: "In my experience, he's always got something in mind. I've never known him to not have a strategic position in mind on any important issue ... He sometimes surprises us with what it is."