Meanwhile, a former head of the Royal Navy has warned that Britain is at risk from terrorists and traffickers because of the lack of boats that patrol UK waters.

Lord West described the situation as a "complete mess" as three Border Force vessels are left to patrol 7,700 miles of coastline, the Daily Mail reports.

This follows the deployment of one to the Aegean Sea to help with the migrant crisis and after aerial surveillance of Britain's shores was scrapped in January.

Lord West told the newspaper: "We are taking a calculated risk with our own territorial waters.

"Already we have seen these illegal immigrants and I don't believe there aren't clever traffickers using the smaller ports to send them and I'm sure terrorists are aware of the route too.

"We need to get a grip on this. We are taking a gamble that nothing will ever happen in our seas and that is a risky view to take given the dangerous world we are in."