Home Office figures show the UK Border Force intercepted 200 illegal migrants every day in the month prior to Britain’s referendum on leaving the European Union (EU), and MPs admit this number is just “the tip of the iceberg”.

The figures were obtained by the Daily Express under the Freedom of Information Act. They show that some 24,800 migrants were caught tryingly to enter the UK illegally during the first six months of 2016, rising from 3,600 in January to 5,900 in June – equivalent to one interception every eight minutes.

Number of illegal entry attempts detected at juxtaposed border controls in 2016:

Source: Home Office

The figures only cover illegal migrants caught at juxtaposed border controls in Calais, Coquelles, Dunkirk, Lille, Paris, and Brussels. Hundreds more have been discovered at British ports, while the number found deeper in the country’s interior has trebled to 27,800 over the last three years.

Research is limited on migrants infiltrating the UK by less conventional routes, for example via the country’s “defenceless” small airfields and “porous” maritime borders.

David Davies MP, who represents Monmouth, described the Express findings as “truly horrendous and shocking”.

Charlie Elphicke MP, whose Dover constituency sits just a few miles across the Channel from Calais, agreed it was “truly shocking 200 migrants tried to break into Britain every day in June. These figures underline why it was so vital to dismantle the Calais Jungle.”

The crime-ridden migrant settlement was demolished in late 2016, initially swelling the so-called “wildcat encampments” which now litter the streets of Paris. But reports now indicate that migrants are returning to the area in their hundreds, as they did following previous failed attempts to evict them.

Rob Whiteman, who headed the UK Border Force – then known as the UK Border Agency – from 2011 to 2013, estimates that around one million illegal migrants are already living in the UK.