More than 3,000 Teamsters members have gone on strike at the Canadian Pacific Railway after contract talks failed to reach an agreement before the midnight deadline.

However, a strike by the railway's 1,800 Unifor members was averted when a tentative agreement was reached in Montreal just minutes before the strike deadline.

Labour and Status of Women Minister Kellie Leitch, who had been involved in the bargaining effort, made her feelings clear in a statement issued after the talks failed.

"I am incredibly disappointed that the TCRC failed to reach an agreement with CP Rail," she said.

"Due to this reckless disregard for Canadians and the Canadian economy, our government will review all available options to end any work-stoppage expediently, up to and including the introduction of legislation in Parliament."

Back-to-work legislation possible

The Conservative government joined contract talks between Canadian Pacific and unionized staff on Friday in a bid to stave off the strike, but it also began laying the groundwork to introduce back-to-work legislation. The government put the legislation on Parliament's notice paper for Monday, meaning it could pass it into law soon after any strike.

It was unclear early Sunday morning exactly how rail service might be affected by the labour action, or whether further contract negotiations were planned.

A spokesman for the Teamsters suggested last week that any disruption of service would have a widespread effect on industries that rely on trains, and that CP managers and other staff would be hard-pressed to maintain service.

I am incredibly disappointed that the TCRC failed to reach an agreement with CP Rail. - Labour and Status of Women Minister Kellie Leitch

Commuter rail service in the Montreal area could be also disrupted. The regional authority Agence Metropolitaine de Transport tried and failed to secure an injunction that would have forced CP to maintain passenger rail service for the 19,000 daily commuters who use the CP-run train routes.

Canadian Pacific said last week that in the event of a strike it would "implement its extensive contingency plan by deploying qualified management employees to maintain a reduced freight service on its Canadian network."

Federal Agriculture Minister Gerry Ritz said Friday that the government would "look at all the tools they had available" to ensure the economy didn't suffer if a stoppage occurred.

In 2012, the federal government passed legislation to force an end to a nine-day strike by about 4,800 striking members of the Teamsters union and CP Rail employees.

It was estimated at the time that a prolonged strike would cost the Canadian economy $540 million a week.

Unifor members to vote

The Unifor members, whose collective agreement expired on Dec. 31, conduct safety inspections on all rail cars and locomotives, as well as maintenance and repairs.

Unifor issued a statement just after midnight that said ratification votes by members across the country would be scheduled over the next three weeks once local presidents and workplace chairpersons have had a chance to review the accord.

"This was a very difficult set of negotiations, but I'm pleased that we were able to break new ground in several different areas," Unifor National President Jerry Dias said in statement.

Unifor Local 101R's Tom Murphy said "We were able to negotiate a new agreement that addresses the concerns raised by our members."

Canadian National reaches deal

In another development, Canadian National says it has reached a tentative labour agreement with the union representing its train engineers in Canada.

The deal with the Teamsters Canada Rail Conference covers about 1,800 locomotive engineers. It will be put to a ratification vote by mid-April, when results will be made public, Canada's largest railway said.

The Montreal-based rail operator did not disclose the agreement's details, pending the vote

CN is still in talks with Unifor, the union that represents about 4,800 workers, including clerical employees and truck operators.