Downing Street insists the government vows to continue working closely with the French authorities after Labour demand compensation from France over the chaos at Calais.

Acting Labour leader Harriet Harman quoted Freight Transport Association estimates that the crisis is costing hauliers £700,000 a day, as thousands of trucks are stuck on closed sections of the M20 in Kent under Operation Stack.

She said David Cameron had ignored repeated warnings about the crisis developing in the port of Calais, where as many as 5,000 migrants are living in a makeshift tent city awaiting their chance to cross the Channel to the UK.

In a letter to the Prime Minister, Ms Harman told David Cameron: “It is wrong for UK businesses and families to face these costs given border security failures in France.

“Your discussions with the French government should therefore include a request for compensation backed up by any diplomatic pressure that may become necessary. Compensation should cover all losses.

“Over the last few days, your approach has been devoid of any serious solution to the crisis.”

A Downing Street spokesman said: “As the PM has said, playing a blame game is not going to offer a solution for anyone. What we are focused on is working closely with the French authorities and taking action to both boost security and reduce disruption for hauliers and businesses.

“We welcome the French police reinforcements, which have helped to strengthen security at Eurotunnel.”

The call came a day after Mr Cameron telephoned French President Francois Hollande to discuss their response to scenes of migrants besieging the Channel Tunnel entrance at Calais.

Measures promised by Mr Cameron, including more sniffer dogs and fences, were dismissed by hauliers’ representatives as “a sticking plaster”.

On Saturday, Kent Police kept Operation Stack in place on the coastbound carriageway of the M20 between junctions 8 and 9 – Maidstone to Ashford – with non-freight traffic able to rejoin the motorway south of this stretch.

Rival protests were held in Folkestone, with a group called Folkestone United calling for local people to show solidarity with the migrants, and the far-right English Defence League holding a counter-demonstration.

After chairing a meeting of the Government’s emergency Cobra committee on Friday, Mr Cameron said scenes of migrants breaking through fences and hanging on to lorries as they try to enter the Tunnel “unacceptable”, adding: “We are absolutely on it. We know it needs more work.”