The tit-for-tat trade spat between the Liberal government and Boeing over the future of the Super Hornet fighter jet purchase escalated Thursday with an acknowledgement that federal officials have been instructed to break off contact with the U.S. aerospace giant.

"We have suspended discussions with Boeing and that is what we have decided," Steve MacKinnon, the parliamentary secretary for the public works minister, told reporters following a speech to defence contractors.

Last March, the federal government submitted a request to the Pentagon for a government-to-government purchase of 18 Super Hornets, on an urgent basis, to fulfil what the Liberals have claimed is a capability gap in the fighter jet fleet.

As part of that request, National Defence and Public Works officials hold regular discussions with the aircraft-maker in order to iron out details and deliver the specific requirements of the Royal Canadian Air Force.

It is those talks that have been suspended, according to MacKinnon.

"There are lots of things we can talk to them about, but we have cut off those discussions," he said.

The dispute, which had largely played out behind closed doors, spilled into the open Wednesday when Defence Minister Harjit Sajjan publicly called out Boeing in front of a room full of defence contractors over the company's commercial trade challenge involving Quebec-based Bombardier.

The public rebuke prompted Boeing to scrap the planned unveiling of its Canadian industry partners for the Super Hornet program Thursday morning.

The company cited the "current climate" for the decision.

"It is not the most opportune time to share this good news story," said Boeing spokesman Scott Day in a statement, issued shortly before the briefing was to take place at an Ottawa defence industry trade show.

Trade complaint

Boeing has been engaged in a very public battle with Canada's Bombardier. The U.S. aircraft maker wants trade regulators in Washington to investigate subsidies for Bombardier's CSeries aircraft, claiming they allow the Canadian company to export planes at well below cost.

On Wednesday, Sajjan called on Boeing to halt its trade complaint against Bombardier.

He also upped the ante in the Liberal government's threat to cancel the planned sole-source purchase of 18 Super Hornet fighter jets by suggesting there were alternatives to the interim procurement.

"The interim fleet procurement requires a trusted industry partner," Sajjan said. "Our government is of the view their action against Bombardier is unfounded. It is not the behaviour we expect of a trusted partner, and we call on Boeing to withdraw it."

Defence Minister Harjit Sajjan used his speech Wednesday at CANSEC to blast Boeing for its trade complaint against Quebec-based rival Bombardier. (Adrian Wyld/Canadian Press)

MacKinnon kept the pressure up on Thursday.

"We certainly hope they'll reconsider their recent actions, which are not friendly and not in Canada's interests," he said.

Sajjan's office refused to comment on the matter Thursday.

"Minister Sajjan's comments [Wednesday] speak for themselves and we do not have anything to add," Jordan Owens, the minister's spokesperson, said in an email.

Canada had announced plans to buy 18 Super Hornet fighter jets as a stopgap measure to beef up its legacy fleet of CF-18 fighter jets, which were also produced by Boeing. Sajjan said at the time Canada didn't have enough jets to meet its Norad and NATO obligations.

Boeing's commitment to Canada "has been, and remains, unwavering," Day said on Thursday.

The company's operations in Canada account for 14 per cent of the country's aerospace industry. That includes 560 companies that provide parts to Boeing commercial airplanes and 2,000 company workers in the country.

"Boeing has provided reliable solutions to Canada's defence and security needs, and we respect the mutual trust we have established with the Canadian Armed Forces through the successful execution of several key programs, including the CF-188 Hornet, CC-177 Globemaster III and CH-147 Chinook," Day said.