The federal government tabled back-to-work legislation Monday afternoon to end the Canada Post lockout, the second time in a week it moved to end a work stoppage.

Federal Labour Minister Lisa Raitt introduced the bill in the House of Commons, which would have an arbitrator pick one side's offer over the other. The government tabled similar legislation to end a strike by Air Canada employees.

Raitt wants the bill passed within a few days to get the mail moving again. The House of Commons is also expected to rest for the summer on Friday.

However, Canada Post and the union are now talking after an unproductive weekend failed to make any progress towards ending the lockout. Last week, Canada Post suspended urban operations after nearly two weeks of 24-hour rotating strikes by workers.

As Raitt spoke to Parliament, members of the Canadian Union of Postal Workers (CUPW) were demonstrating across the country, trying to rally public support to their cause. By Monday evening, they were occupying the offices of Conservative MPs across the country.

Demonstrations are scheduled to continue until Friday.

"We've done everything in our power to achieve a negotiated settlement with as little disruption to the public as possible," Mike Palacek, a postal worker from Vancouver, said in a news release.

"Canada Post's response has been to suspend all of its services, lock us out, and wait for back-to-work legislation."

Raitt said the two sides have had more than enough time to come to a deal.

"It is both parties at the table who are negotiating and have been unable to obtain an agreement," she said.

But the opposition parties say the bill sets a dangerous precedent on the side of employers.

"The government picked sides today," NDP MP Chris Charlton, the party's chief Opposition whip, told CTV's Power Play. "The minister introduced a bill that was very employer friendly. It pretty much said, ‘These are the conditions employers need and we are going to put those into legislation.' We cannot support a piece of legislation that interferes with free collective bargaining."

Liberal MP and labour critic Rodger Cuzner said the government's threat of back-to-work legislation was what caused the lockout in the first place.

"Once (Canada Post) heard that back-to-work legislation was coming for Air Canada, they triggered the lockout and that just tipped the whole field," Cuzner said.

Some critics say the government's quick move towards back-to-work legislation may have some workers wondering about the point of striking.

"It is very much a shift and it is really putting management interests, whether they are government or private, ahead of employees," Laurel Sefton MacDowell, a labour relations historian at the University of Toronto, told The Canadian Press.

"It's very disturbing."

Raitt defends bill

Speaking to reporters after tabling the bill, Raitt said the work stoppage has hurt the economy.

"We're here to put people back to work," she said. "We're acting on the interest of Canadians and the national economy."

If legislation is passed before Canada Post and the union make a deal, employees would return to work and an arbitrator would have 90 days to study the proposals made by both sides before coming up with a final settlement. The arbitrator will pick one of the two offers put forward.

Raitt said the risk of getting a worse deal from binding arbitration instead of a negotiated settlement is "the danger of asking Parliament to settle your dispute."

Raitt said she is open to facilitating negotiations between Canada Post and the union.

Earlier, Jon Hamilton, spokesperson for Canada Post, said the Crown corporation is still hoping to negotiate a settlement with the union before the government steps in.

However, the two sides have failed to gain any ground in recent negotiations, and scheduled face-to-face talks failed to materialize on Sunday.

Canada Post says it has lost $100 million because of the job action.

The New Democrats have signalled their intention to vote against the back-to-work bill, though they will be unable to stop the majority Conservatives from passing the legislation.

Raitt tabled similar legislation last week that would have forced striking Air Canada employees back to work, but the two sides worked out a last-minute agreement before second reading.

Postal workers had been staging rotating strikes across the country since June 3 before they were locked-out.

The Crown corporation has said the main sticking point in the dispute is the union's demand for staffing levels beyond the capability of Canada Post, adding that wages were not the key disagreement.

The union has been emphasizing working conditions and safety issues, as well as arguing that new employees would receive inferior wages and pensions.

Ottawa legislated striking postal workers back to their jobs in 1997, after they were off the job for two weeks. That was the last time the postal workers went on strike.