Immigration from mainland Europe will “change the face” of Britain and lead to swathes of the countryside being built over to provide new homes for migrants, a Cabinet minister has warned.

Chris Grayling, the Leader of the House, said new roads will be needed to avoid “gridlock” and hitherto protected Green Belt land will disappear under housing estates in order to cope with the influx, if Britain stays in the European Union.

In an interview with The Daily Telegraph, Mr Grayling said Britons must vote to leave the European Union in the referendum next month and then immediately introduce new laws to ban migrants from coming to the UK to look for work, he says.