Dover and Calais are facing “economic catastrophe” because of Brexit, and both the UK and the EU are allowing the two ports to drift towards disaster, a leading French politician has said.

Xavier Bertrand, a former French minister and president of Hauts-de-France, has called on Emmanuel Macron to break the EU ban on bilateral talks to salvage the situation and have direct negotiations with Theresa May.

“The way things are going, we are going to be left standing staring at each other like strangers. It’s madness, pure utter madness,” he said.

Xavier Bertrand said the French parliament and President Macron must be pressed to talk to the UK directly. Photograph: Lisa O'Carroll

He believes the challenge facing the ports and Eurotunnel, which are used by 16,000 trucks a day, is just as important as the Irish border, yet does not get the same attention.

His intervention comes as the EU’s chief Brexit negotiator, Michel Barnier, prepares to tell all member states to step up their planning for no deal, at a meeting on Friday.

Bertrand believes this does not go far enough and that talks need to swiftly move to local planning or time will have run out for practical contingencies including border inspection posts and customs clearance checks.

“If there are delays of two minutes there will be queues of 27km on both sides – that’s 54km [34 miles]. Even at the moment you see queues of 1km to the tunnel – and that is where there are no checks. Imagine what it will be like with checks,” he said. “We need to pressurise the French parliament and President Macron of the need to talk to the UK directly.”

He acknowledged this would be politically difficult because it would breach the strict EU ban on bilateral talks. “It is against the negotiating rules at the moment but not to talk is an error,” he said. “The French and British governments have to talk to each other to find a solution, otherwise we are heading for something catastrophic. Both governments need to talk to each other to find solutions.”

Bertrand has now made five trips to Britain to try to impress upon politicians and officials the need to swing contingency plans into action. He said his talks had been frank, but Dover-Calais was not “first in line in negotiations” meaning nothing was happening. “I am going to one more time try to increase the pressure and warn people about the dangers: what about the catastrophe?” he said, but time was running out.

Bertrand, who was a French minister three times and was considered a runner for prime minister under Macron, said he wanted a good deal for Britain. “It is nonsense to think anyone wants to punish them,” he said.

In the absence of advanced planning on the British side, he revealed that Calais was prepared to solve the problem of space for checks in Dover. It has already brought 17 hectares (42 acres) of land, which could house inspection posts for sanitary checks and logistics warehouses. France is planning to recruit 700 new customs officials, some of whom will be in Calais.

Calais also wants to test a new “Fastpass” virtual queuing system which will allow passengers and hauliers to preload passport information and cargo information along with their ferry and tunnel booking. It is estimated this could enable 500 passengers an hour to be waved through border controls.

But they are in a race against time to build the border inspection facilities, which involve giant refrigerated channels for trucks carrying fresh produce, and need political agreement for the release of funds.

“We have the space for the logistics and the customs checks to maintain fluidity,” he said, but he did not want to end up begging for money on the eve of Brexit. That would mean a disaster already stitched in to the future.

Bertrand made his remarks after a private meeting with Conservative party MPs in Westminster including hard Brexiter Daniel Kawczynski, Andrew Bowie and Tom Tugendhat, the chair of the foreign affairs select committee.

Bertrand said he used to be optimistic that a solution for Dover-Calais would be found, but he now despaired as he could see that Brexiters thought no deal was “still a way”.

He said: “It showed me the difficulties internally within the UK. I asked them straight out if it was true that the people were being advised to stockpile food, they said it was. That confirmed that they think no deal is an attractive possibility.

“For a long time I was very optimistic. I was afraid, but I believed the common sense and pragmatism would prevail. Now I am losing my sense of optimism but I want to find a way to avoid that catastrophe if things are not going to get better. I’m going to call on the French government and the French president to make the voice of common sense heard.”

He is concerned that his own efforts at contingency planning will hit the buffers because there is no cross-border communication at a political level. “I don’t think there is enough awareness. Many politicians think it is all automatic and somebody will take care of Calais,” he said.

Bertrand has made some progress including last week’s agreement for France to hire 700 new customs officials for nationwide deployment. But it is not clear how many will be allocated to Calais.

In March, Bertrand and the boss of the port of Calais said the Channel would be 10 times worse than the Irish border.