Members of Parliament could be in for many more late nights, now that the Liberals have passed a motion to extend the House of Commons' sitting hours on a day-to-day basis, between now and June.

By a vote of 168 to 144, the Liberals got the backing of the NDP to put in place a system that will allow ministers, in co-operation with at least one opposition House leader, to request that the House not adjourn until midnight to keep debating government legislation.

The move comes after the Liberals accused the Conservatives of obstructing the government's legislative agenda by put up long lists of MPs to speak to bills—including ones they support—prolonging the time it takes legislation to come to a vote and move to the next stage.

In presenting this motion just ahead of the five-week stretch of sitting before Parliament wraps for the year, the government said that if the Official Opposition wants more time to debate, this programming change will allow for it.

"It has been a source of frustration to not know how many speakers are going to be put up, specifically by the Conservatives, and that is frankly obstruction by stealth," Government House Leader Mark Holland told the House during debate on the motion on Monday.

The motion came to a vote on Tuesday night after MPs spent time on Monday and Tuesday voicing their views on this change to their working hours. 

Opposing the move and rejecting the accusation of being obstructionist, the Conservatives are concerned that more late-night sittings may put a strain on House of Commons resources and result in fewer committee meetings.

The Conservatives tried to pass an amendment to the motion, seeking assurances from a top House official that there would not be any impact on regularly scheduled committee meetings on days with late sittings. The amendment was defeated, despite the Bloc Quebecois backing it.

Speaking to reporters on Parliament Hill on Tuesday, Conservative House Leader Andrew Scheer said the motion will "have the effect of stifling accountability," and defended the number of MPs from his party rising to speak to bills.

"When members of Parliament want to represent their constituents, when they want to speak on behalf of people who have told them that they have a concern with a bill—either what’s in the bill or what’s not in the bill— then it’s the role of those members of Parliament to bring those concerns to the House of Commons," he said.

In supporting the motion, the NDP made the caveat that in order for extended sitting hours to work, advance noting is going to be key to show respect to the employees who help make Parliament function.

The government has not calculated what the additional cost will be to the House of Commons if many more midnight sittings are ahead—requiring staff, translators, security and others to stay late—but, Holland has vowed to keep it within the pre-existing House administrative budget.

The motion also gives the government the power to "without notice" immediately adjourn the House of Commons a few days early at the end of the fall sitting in December, and in June when MPs wrap up for the summer.