The Scottish salmon industry has called on ministers to urgently intervene to stop Brexit-related delays to the transportation of fresh fish to France.

It comes after the Brexit opportunities minister, Jacob Rees-Mogg, admitted he was wrong to say there would be no delays at the port of Dover caused by the UK leaving the EU.

Tavish Scott, chief executive of trade body Scottish Salmon, held a meeting with the fisheries minister Victoria Prentis on Tuesday morning after fish became stuck in the gridlock on Kent roads a fortnight ago.

“Fresh salmon from Scotland will normally arrive in France the following morning, but in recent weeks there have been delays of up to 48 hours due to queues on the UK side of the Channel – and there are concerns of repeat problems,” the organisation said in a statement.

Normally fresh salmon would be available to the chefs in France, the biggest market, within three days of harvesting. But the industry says the past two weeks have seen days when it has been unable to get fish into France at all.

Before Brexit, hauliers could transport their product across the Channel without any checks.

Now all food has to be accompanied by customs and health and safety documentation, with fish directed to Boulogne-sur-Mer, near Calais, where mandatory controls, including checking veterinary certificates, are conducted.

A spokesman for Scottish Salmon said the fishing industry model was selling fresh fish on “day one for consumption on day three”.

But the delays on the Kent roads have meant delays of up to four days – and sometimes the loss of entire sales.

“We had one day where we could not get any fresh into France at all,” the spokesman added. “These are perishable products. Unlike a tin of beans they cannot be sitting in a queue on the back of a truck.

“The impacts of the border controls were identified, mitigation measures were identified but for some reason the government has decided not to implement them.”

The industry is calling on the government to put short-term measures in place to triage haulage, enabling refrigerated trucks with perishable goods to be prioritised in the event of future gridlock on the Kent roads.

But it also wants a longer-term solution put in place.

“Fresh Scottish salmon is perishable and needs to arrive with customers as quickly as possible,” said Scott. “Following today’s constructive meeting, we are hopeful of swift action.”

France is the top market for the fish, where it holds prestigious status with chefs and restaurants.

“The concern is that if the government don’t do something about this, our customers will just go to Norway, where they can guarantee the supply chain,” said the spokesman.

Generating more than £600m in sales, Scottish salmon is the UK’s single biggest food export.

The industry is at a disadvantage to Norway, which has access to the single market as it is a member of the European Economic Area, an option rejected by the British government.

The industry is also facing the threat of a trade war with some speculating the EU will target iconic exports such as salmon in event the new prime minister acts on the threat to tear up the Northern Ireland Brexit arrangements.

The Department for Farming, Environment and Rural Affairs has been approached for comment.