NDP Leader Tom Mulcair may soon find himself and his party on the other side of the procedure and House affairs committee microscope.

On Thursday morning, the House of Commons took the rare step of passing a motion that orders Mulcair to appear before the committee to answer questions on allegations of "improper use of House of Commons resources for partisan purposes."

Although it declines to go into further detail on exactly what alleged improprieties will be under investigation, the NDP has recently come under fire for using taxpayer funds on "outreach" offices in Montreal and Quebec City, as well as separate allegations related to House-funded bulk mailings during byelections.

The motion was introduced by Minister of State for Labour Kellie Leitch.

Here's the prepared text, courtesy of the government whip's office:

That the Leader of the Opposition be ordered to appear as a witness at a televised meeting of the committee to be held no later than May 16, 2014.

The move, which appeared to take the NDP completely by surprise, relied on a rarely-used provision in the Standing Orders that gives ministers a second chance to force through a motion initially denied unanimous consent.

While the NDP could still have blocked the motion by having 25 MPs rise in objection, it appears that they were unable to muster the necessary show of force on what was, quite literally, a moment's notice — and, it's worth noting, without the help of their Liberal colleagues, who remained seated.

Under the motion, Mulcair is required to take the stand on or before May 16, which means the committee will likely begin its investigation into the allegedly improper spending after it wraps up its review of the election bill, which is scheduled to be back in the House by early May.

UPDATE: They may have been caught by surprise this morning, but it didn’t take long for the New Democrats to parry.

Shortly after the House adopted the motion ordering Mulcair to appear before the procedure and House affairs committee, New Democrat MP David Christopherson served notice that he’ll be asking the committee to expand its investigation to cover "the many partisan activities undertaken by [the] government" – specifically, “by the Prime Minister’s Office (PMO) and the Conservative Research Group [sic] (CRG).”

(In fact, unless there’s been a name change, "CRG" actually stands for "Conservative Resource Group," although presumably the motion, if passed, would still apply.)

To that end, the NDP is proposing that both Mulcair and Harper be invited — not ordered — to appear before the committee.

The New Democrats also want a guarantee that any time that the putative investigation takes away from the current review of the election bill be added to the current schedule.

The motion could be called for debate as early as next Tuesday, although that, of course, is no guarantee that it will actually pass.

Still, by putting it on the record — and ultimately, if futilely, supporting it in a vote — the NDP can at least claim that their leader will be appearing before the committee willingly, and not only because he’s been ordered to do so.

The full text of the NDP motion: