A disused private airport in east Kent is to be used as an emergency lorry park to provide a short-term solution to ease road congestion caused by the Calais crisis.

The transport minister, Lord Ahmad, said Manston airfield, near Ramsgate, would be temporarily pressed into service the next time Operation Stack was enforced to help reduce pressure on the M20.

Lorries containing livestock, perishable and other “quick to market” goods were to be prioritised and given direct access to ferries without having to queue in Operation Stack, which at its peak has seen 7,000 vehicles stretched back for 36 miles.

“We have found a viable short-term solution to the disruption residents and industry in the M20 corridor from Dover to Maidstone have been experiencing in recent weeks as a result of Operation Stack,” said Ahmad.

The highways authorities are also understood to be working on plans to keep two-way traffic flowing on the M20 between Maidstone and Dover. Parts of the M20 have been repeatedly closed under Operation Stack, which was last in force on Sunday, causing traffic chaos across south-east Kent.

Damian Collins, the Conservative MP for Folkestone and Hythe, welcomed the use of Manston airport, saying: “It will relieve a large pressure from the people of Folkestone and Hythe.” Plans to use part of the car park at Ebbsfleet station near Dartford as a lorry park for more than 1,000 vehicles are due to be put into practice shortly.

The proposal to use the old RAF Manston airfield, which closed as a commercial airport last year, was strongly resisted by local MPs, who feared it would block roads into the Thanet area, 20 miles from Dover. One Conservative MP, Sir Roger Gale, called the move “insane”.

On Tuesday tourists and lorry drivers faced delays crossing the Channel while one undersea tunnel was closed for an inspection owing to what Eurotunnel called an “anomaly”. It was not clear whether the problem was an issue with the tracks, the presence of a migrant or another incident.

In France, a police source told the news agency AFP that hundreds of migrants were seen overnight next to the Eurotunnel terminal. Of the 600 attempts they made to get into the site, about 400 were repelled by authorities. Of the other 200 people, 180 were caught within the site and removed and a further 20 were arrested.

Despite the morning delays, roads leading to Dover and the Eurotunnel terminal in Folkestone remained relatively free of traffic on Tuesday afternoon. There was some slow-moving traffic eastbound on the motorway, but Operation Stack was not in place.

Delays caused by the recent incursions have had a knock-on effect on British businesses. One Scottish seafood exporter said it had lost £100,000 worth of business because of the migrant crisis.

James Cook, managing director of DR Collin, based in Eyemouth in the Scottish borders, said the problems at Calais were having a big impact on his business. Scotland exported £461m of seafood to Europe last year.

“This has gone on now for six weeks and we’ve had problems almost daily,” Cook said. “We cannot complete our jobs, we cannot deliver our product to our customers. There has been lots of frustration and lots of financial implications.”

He added that the company was now missing the chance to catch up after poor fishing owing to bad weather over the winter and spring.

Meanwhile, a former government adviser has said Britain should offer to take in some refugees from Calais in a bid to resolve the crisis, similar to the agreement struck ahead of the closure of the French Sangatte camp in 2002.

Nick Pearce, who worked as an adviser to the former home secretary David Blunkett at the time of the Sangatte emergency, said: “We should again bring in the United Nations to register migrants, offer those seeking refugee protection a proper process for applying in France for access to places on the UK’s refugee resettlement programme and give those with family members in the UK a ‘work visa’ to enable them to work without calling on public funds.”

Pearce, now head of the IPPR thinktank, conceded the British public “will take some convincing” of the approach. “But it would be the humane, as well as practical, thing to do,” he said. “And if ministers had the courage to do it once before, they can do so again when circumstances demand it.”