Eurotunnel says 37km of new security fencing around its site at Coquelles in Calais has reduced attempts by asylum seekers to board lorries to get to the UK to “virtually zero".

The fencing was put in as part of a package of measures aimed at curbing attempted incursions by migrants, following weeks of disruption and delays at the French terminal.

In July, Home Secretary Theresa May announced an extra £7 million to improve security around the French terminal, primarily for better fencing but also to treble the number of security staff.

In a statement, Eurotunnel said as a result of a “substantial programme of investment” to deal with public safety, the Coquelles site “has now been restored to its habitual high level of protection.”

It said that in the last four weeks the Channel Tunnel site in Coquelles, which carries nearly 400 trains per day has been operating to its normal levels of security.

The company added that attempted incursions had reduced to almost zero and there has been no disruption to services.

Last Thursday Eurotunnel recorded its best operational performance for the year, with close to 6,800 trucks transported in both directions, despite the increased level of security controls.

The remarkable change in fortunes follows weeks of chaos over the summer, when disturbances at the Calais terminal caused by migrants led to Operation Stack being implemented for a record-breaking 37 days.

Hauliers estimated that the cost to those caught up in the operation to be £700,000 a day and £250 million to the UK economy as a whole.

Chairman and chief executive Jacques Gounon said: “I would like to pay special tribute to the work of the men and women who provide the security that keeps this vital artery for European industry, culture and tourism open.”