Eurotunnel, the company that operates the channel tunnel, has been hit by security costs caused by rising problems with migrants around Calais.

The Paris-based company said it has already spent €13m on security measures in the six months to June 30, the same amount as it spent during the whole of last year.

“The high concentration of migrants in the Calais area has caused, and may continue to cause, disruption to traffic and additional security costs,” the company said.

“If this situation continues, or even intensifies, during the second half of the year without the French and British authorities taking the necessary measures incumbent upon them, it could affect the group’s traffic and expenditure for the 2015 financial year.”

Eurotunnel gave a brief update on the chaotic situation that has seen the two ferries it owns occupied and vandalised by the workers it previously employed to run them.

Eurotunnel said: “The French secretary of state for transport is seeking to establish a dialogue between the parties to resolve the situation.

Eurotunnel recently agreed to sell its MyFerryLink business to rival operator DFDS after the UK competition authorities ruled that it controlled too much of the cross-Channel market.

Ferry workers have been protesting against the sale and potential job losses. They occupied ships on Tuesday and ran amok, blocking the Channel tunnel with a wall of blazing tyres.

The company’s total operating costs rose 10 per cent in the first half to €397m, although much of this was related to increased services.

Eurotunnel said the UK government has agreed to reimburse it €4.7m and it had asked for €9.7m from the Intergovernmental Commission, the regulator of economic and safety issues related to the tunnel, which is run jointly by the French and British.

Despite the migrant problems, the tunnel operator saw revenue rise 9 per cent to €649m as the strongly recovering UK economy, and more moderately recovering eurozone economies helped push up freight and passenger traffic.

The company’s pre-tax profit rose to €40m, up from a loss of €3m in the same period last year.