The head of Eurotunnel on Monday warned that Britain's decision to leave the European Union could lead to an increase in the number of migrants trying to enter Britain via Calais on the French coast.

"There could be increased migrant pressure during the summer and because of Brexit as migrants will try to cross at any cost before it (Brexit) is implemented," Jacques Gounon said on Monday after last week's referendum vote to quit.

Gounon was speaking at a news conference in Calais, the main entry and exit point between Britain and France via road, sea and the Eurotunnel rail link.

A migrant camp that became known as 'the jungle' grew up there last year, becoming home to thousands hoping to head for Britain and causing transport disruption until tighter security made leaping on lorries and walking through the tunnel more difficult.

Gounon was presenting extra security arrangements which include the deployment of two drones equipped with cameras to fly around its Coquelles terminal in northern France.

Shares in Eurotunnel have fallen 27 percent since Thursday's referendum in which Britons voted 52 percent to 48 to leave the European Union.

The drop has come despite Gounon's reassurances that the business would not suffer as a result.-Reuters