The chief executive of Eurotunnel, the company that operates the tunnel between Britain and France, is leaving over differences about how the organisation should be managed.

Chief executive Philippe Lazare will step down on 31 December to be replaced by chief financial officer, Richard Shirrefs.

The company did provide any details about Mr Lazare's disagreement with Eurotunnel's management team.

Earlier this year the outgoing chief executive said that French authorities were not doing enough to solve the problem of illegal migrants trying to use the Eurotunnel as means to enter the UK.

In a July memo, he identified a nearby centre run by the Red Cross in Sangatte, near Calais, as the main trouble spot and claimed it was a "logistics base" for criminal groups involved in smuggling illegal migrants.

Eurotunnel claimed to have intercepted 18,500 stowaways during the first half of the year. The company has spent considerable funds boosting security.