Leave-backing MPs have welcomed assurances from the French port of Calais that there will be no extra checks on lorries if Britain leaves the EU without a deal in March.

Port boss Jean-Marc Puissesseau said Calais had been preparing for Brexit for a year and would be ready to cope when the UK leaves the EU on March 29, whether there is a deal or not.

He said he was “shocked” by the “disrespectful” decision by Transport Secretary Chris Grayling to spend more than £100 million on ferry services from alternative ports to ease the pressure on the Dover-Calais route.

Mr Puissesseau told BBC Radio 4’s Today programme: “We are preparing for no deal since one year in Calais and on March 29 we will be ready.

“When Mr Grayling came to Calais, we told him that we will be ready.

Lorries head for Dover during a trial of Government plans to hold trucks at Manston airfield in the case of tailbacks at the port (Gareth Fuller/PA)

“We will not check the trucks more than we are doing today, with the migrants. We will only be asking of the drivers that they have their customs declarations, but we will  not stop or ask more than we are doing today. It is very clear.”

His comments came days after a leaked report suggested delays of as little as 70 seconds per truck at Dover could cause traffic jams which would take six days to clear.

They follow a Government exercise to trial the use of Manston airfield in Kent as a holding centre for trucks queuing to reach Dover in the event of disruption

Mr Puissesseau said the Government’s spending on alternative ferry routes would help Calais’s rivals for cross-Channel traffic, including by opening a new link between Ramsgate and the Belgian port of Ostend.

“I am very shocked,” he said. “I consider it disrespectful to Calais and to Dover what has been decided by Mr Grayling and the British government.”

Brexit-backing Conservative MP Nadine Dorries said Mr Puissesseau’s comments represented “the reality, as opposed to Project Fear Mk III”.

Bolton West MP Chris Green, who quit his role as a Transport Department aide in protest over Brexit, said: “Looks like trade with EU business post-Brexit, will be fine so let’s stop with project fear.”

Tory Brexiteer Marcus Fysh said the port official’s comments “give the lie to Remain ministers’ scaremongering”.

Brexit minister Chris Heaton-Harris said he hoped traffic would continue to flow as freely as Mr Puissesseau suggested, but warned the European Commission could demand additional checks.

“I would like to think it would be as free flowing. But the European Commission can insist on extra checks at the border,” he told the Commons Exiting the EU Committee.

“We would expect there to be a tiny bit more of a check than the mayor of Calais said. But maybe he is privy to information because France can apply to the European Commission to waive checks.”

A Department for Transport spokeswoman said:  “We welcome Mr Puissesseau’s comments and continue to work with colleagues across the Channel to manage all eventualities.

“We hope he will continue to join us in putting continued pressure, whatever circumstances arise, on the French Government and European Commission who are responsible for tariffs and customs checks.

“It is a top priority for Government is to ensure that the Port of Dover and the Eurotunnel continue to operate at the maximum possible capacity. However, it is only right that as a sensible Government we should make plans for all eventualities.”