At the same time, 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.
The Teamsters Canada Rail Conference union represents 3,300 locomotive engineers and other train workers at CP.
In a statement issued Sunday morning CP said it would deploy management personnel to operate a reduced freight service on its Canadian network.
The railway also said it would be advising its customers on how they would be affected by the work stoppage.
Labour and Status of Women Minister Kellie Leitch had been involved in the bargaining effort and 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.
Leitch was also clear about the federal government's next course of action.
"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."
The minister urged the union to end the strike immediately and return to the negotiating table.
Teamsters Canada president Douglas Finnson said in a statement that picket lines were being set up across the country and that the rail shut down was underway.
Finnson added that despite the "complete breakdown" of bargaining Saturday night the union had advised CP that its negotiators would remain available to broker an agreement that would ensure "a healthy and safe" work environment for its members.
The union leader also indicated that the railway's most recent contract offer still contained demands for unacceptable concessions.
CP, for its part, contends that it proposed fair options at the bargaining table, including wage increases, better benefit plans and changes to work schedules to improve the quality of life for engineers and conductors.
It was unclear Sunday morning exactly how the labour action would impact rail service.
But a Teamsters spokesman 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.
Commuter rail service in the Montreal area could also be 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.
Federal Agriculture Minister Gerry Ritz stated 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 some 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.
The Unifor members, whose collective agreement expired on December 31, conduct safety inspections on all rail cars and locomotives, as well as maintenance and repairs.
The union 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 chairpeople 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 the statement.
Unifor Local 101R's Tom Murphy said “We were able to negotiate a new agreement that addresses the concerns raised by our members."
Separate negotiations have also been taking place between the two unions and Canadian National Railway (TSX:CNR). Late Saturday, Teamsters Canada announced a tentative three-year agreement had been reached with CN.