OTTAWA -- Mail service came to a halt in Ottawa on Friday as the Liberal government put a rush on legislation ordering postal workers back to work.

The capital, as well as smaller towns in Ontario and British Columbia, and Sherbrooke, Que., were the latest targets of rotating strikes by the Canadian Union of Postal Workers.

In the House of Commons, MPs debated a motion to deal speedily with a bill, tabled Thursday, that would put a stop to mail disruptions across the country.

That fast-tracking motion is to be put to a vote late Friday and, if it passes as expected, MPs will resume debate on the back-to-work bill, concluding with a vote on the legislation sometime in the wee hours of Saturday morning.

The Senate is set to sit Saturday and, if necessary, Sunday, to deal with the bill, which will go into effect at noon eastern time on the day following royal assent.

Despite the rush to pass the legislation, Labour Minister Patty Hajdu encouraged Canada Post and CUPW to remain at the bargaining table.

"They can still pull a deal off," she said.

That said, Hajdu added: "Obviously, we would prefer that the parties are able to negotiate an agreement together but the time has come that we need to be prepared to take action if they cannot."

Hajdu referred to mail delivery as an "essential service" and said small businesses that rely on the postal service to deliver their goods over the busy Christmas season could go bankrupt if the situation isn't remedied quickly.

"And when I say small, I mean really small. I mean people that, you know, sell marmalade or handmade goods, that this is the most profitable time of their year and if they are unable to make their earnings this time of year, they very well might be facing the end of their business."

Labour leaders and New Democrat MPs slammed the government for undermining the collective-bargaining process. The government has removed all incentive for Canada Post to reach a negotiated settlement now that the agency knows workers will be ordered back to work by early next week, they charged.

"The right to strike is an integral part of the collective bargaining process," said Canadian Labour Congress president Hassan Yussuff. "Without it, an employer has no incentive to bargain in good faith, and workers have no recourse to demand a fair process."

Canada Post seems to have convinced Prime Minister Justin Trudeau that Christmas wouldn't come without a back-to-work bill, added CUPW president Mike Palecek.

"The mail was moving, and people know it," he said. "People have been getting their mail and online orders delivered. That was the point of our rotating-strike tactics, not to pick a fight with the public."

NDP Leader Jagmeet Singh accused the Liberals of hypocrisy, professing to believe in the right to collective bargaining while bringing in what he called the "worst, most draconian" back-to-work legislation.

"They've shown their true face ... that this government is not a friend of working people," Singh said

CUPW maintains the bill is unconstitutional and is threatening to challenge it in court.

The union won a court challenge to back-to-work legislation imposed on postal workers in 2011 by the previous Conservative government. The court ruled in 2016 that by removing workers' right to strike, the bill violated their right to freedom of association and expression.

Hajdu argued that her bill is "dramatically different" from the "heavy-handed" approach taken by the Harper government and takes into account the concerns of both the union and Canada Post.

But two independent senators, Frances Lankin and Diane Griffin, wrote Hajdu to express their concern that the bill may not be constitutional. The pair said Hajdu had promised to issue a government analysis detailing how the bill does not violate the Charter of Rights and Freedoms but it still had not materialized by Friday evening.

CUPW members have held rotating walkouts for a month, causing massive backlogs of unsorted mail and packages at postal depots, though Canada Post and the union dispute how big the pileup is.

Canada Post says it could take weeks -- even stretching into 2019 -- to clear the backlog that has built up, especially at major sorting centres in Toronto, Montreal and Vancouver.

CUPW's 50,000 members, in two groups, are demanding better pay for rural and suburban carriers, more job security and minimum guaranteed hours.

Timeline of Canada Post job action

Between 1965 and 2005:

  • 19 strikes, lockouts and walkouts
  • Workers legislated back to work in 1987, 1991 and 1997

2007:

  • No labour disruptions as CUPW strikes four-year deal with Canada Post

2011:

  • 48,000 Canada Post workers begin job action June 2 with rotating strikes
  • Canada Post locks out workers June 14, saying it can't operate under constant threat
  • Conservative government tables back-to-work bill June 20; stoppage ends June 27

2016:

  • CUPW wins challenge of previous back-to-work legislation in the Ontario Superior Court
  • Union and management sign two-year contract Aug. 30 without new disruption

2018:

  • Canada Post workers begin rotating strikes in different cities Oct. 22
  • Labour Minister Patty Hajdu tables back to work legislation Nov. 22
  • Canadian Union of Postal Workers vows to fight in court if bill passes