The Montreal event, scheduled to take place on June 11, was only given provisional status in the draft 2017 F1 calendar that was published by the FIA in September.

It is understood its place was subject to the confirmation that track and infrastructure improvements promised as part of its contract would be completed in time.

Back in 2014 as part of a new deal, it was agreed that a revamp of facilities – including the paddock, control tower and medical centre – would be finished by next year.

But progress at the venue has not moved as fast as originally anticipated, and discussions are now taking place about delaying the completion of work until 2019 rather than next year.

Such a change may require an all-new contract to be drawn up.

Canadian Grand Prix promoter Francois Dumontier attended the United States Grand Prix last weekend for talks with Bernie Ecclestone and FIA president Jean Todt to talk with them about the situation – and he said he was confident matters were heading in the right direction.

“It is now being discussed between the mayor’s office and Ecclestone,” Dumontier told Motorsport.com. “I’m pretty confident that they can reach an agreement that will remove the [to be confirmed] ‘asterix’ from our race.

“There is a proposal to delay the completion of the work until 2019, and if we get agreement on that then we should be fine.”

Canada realistically has until November 30 to sort out a deal with Ecclestone, because that is the date when the FIA is expected to finalise the 2017 calendar.