Last-ditch talks have been launched to find an agreement between the UK and France in the dispute over fishing licences, as the head of the ports of Calais and Boulogne spoke of a disaster if Paris goes through on its threats to clog up trade.

Jean-Marc Puissesseau said he had already received instructions to stop British fishers from unloading in Boulogne from Tuesday while the border authorities at Calais would enforce tougher controls on goods laden trucks.

“It will be a drama, it will be a disaster,” he said. “It will be a chaos in your country because the trucks will not cross, it will be chaos at the ports … It has reached a ridiculous point, I would say.

“I hope that the British and [the French] find an agreement, we find a solution to get out of this point. I know that there is some discussions during the weekend so I do really hope.”

The focus of the row is the shortfall in the number of licences given to French vessels within the coastal waters of the UK and Jersey, a British crown dependency.

The UK has only approved 16 out of 47 applications for French boats to operate in the UK’s coastal waters. A further 14 applications are being considered where evidence of activity in those waters was limited, but 17 applications had been withdrawn by French applicants because of “poor evidence”.

Of greater concern to the French authorities is that 55 boats applying to fish in the waters off Jersey have been turned down by the island’s government due to lack of evidence that they have fished there for 10 days in any of the past three years.

Officials from the European Commission, the UK, France and Jersey were seeking to find a way out of the crisis in talks on Saturday, with Paris having said it will “gradually” ratchet up customs and sanitary controls on freight, make more rigorous checks of trucks coming in and leaving France, and prohibit trawlers from landing their catch in French ports if the dispute was not resolved.

The French government is also considering raising the price of nuclear energy provided to Jersey through subsea cables.

France’s prime minister, Jean Castex, has written to the European Commission president Ursula von der Leyen seeking further EU action on top of the unilateral measures announced, but sources in Brussels said they were hoping to avoid such an escalation.

Boris Johnson has warned of UK retaliation if cross-channel freight is disrupted by the French authorities due to the dispute over fishing licences.

The authorities in Jersey and the UK have repeatedly said they are open to any further evidence from applicants of having operated in their waters.

It is understood the latest talks are focusing on what level of data might be accepted and whether any further flexibility can be found to avert issues at the ports on Tuesday.

In an interview with the Financial Times, France’s president Emmanuel Macron, who will meet Johnson at the G20 meeting in Rome on Sunday, said the row was “a test” of the UK’s “credibility”.

He said: “Make no mistake, it is not just for the Europeans but all of their partners. Because when you spend years negotiating a treaty and then a few months later you do the opposite of what was decided on the aspects that suit you the least, it is not a big sign of your credibility.”

He added: “We need to respect each other and respect the word that has been given.”

Puissesseau told the BBC that finding an agreement was vital. He said: “Don’t you think we have enough problems with the virus? We lost in the port of Calais last year, because of the virus, EUR30m turnover and this year we are again going to lose EUR20m.

“That is EUR50m lost due to a virus and now we will be obliged to bring in controls in our port? I tell you, this economical problem with fishers is a drop of water in the ocean.”