Nearly every Channel migrant arrives in the UK without a passport after being told by smugglers to shred their documents to avoid deportation, Home Office figures have revealed.

       Only 317 – or two per cent – of 16,510 Channel migrants had passports with them when they were picked up by Border Force, according to the data, released under Freedom of Information laws. That means 16,300 – 98 per cent – arrived in the UK without documentation.

       People-smugglers encourage migrants to destroy ID papers because it boosts their chances of securing asylum and makes it hard to deport them as officials have nowhere to send them.

       There are laws, introduced by Labour under Tony Blair, that makes it a specific offence to destroy ID documents in order to aid an asylum claim, but Home Office data show that there have been fewer than 10 prosecutions in four years.

       Border Force and immigration officials are powerless to remove migrants without ID documentation under laws that bar the expulsion of a failed asylum seeker of unknown origin.

       It also makes it harder for UK immigration officials to prove that migrants passed through a safe third country in Europe which would entitle the UK to declare their claims inadmissible and return them to the EU nation in which they should have applied for asylum.

       Migration experts also fear it could be a security risk, allowing potential terrorists to mask their identity as they try to enter the asylum system.

       The Crown Prosecution Service (CPS) has previously warned that the "destruction of documents disables the authorities from establishing where an entrant came from, in order to increase the chances of success of a claim or application and/or to thwart removal".

       In its guidance to prosecutors, it admitted: "These offences have the real potential to undermine the whole system of immigration control."

       Alp Mehmet, the chairman of Migration Watch UK, which obtained the figures, said: "Verifying that those arriving in small boats are who they say they are is all but impossible given they have nearly all destroyed their documents.

       "And yet, in most cases, we take them at their word and let them in even when there are serious doubts about their age and identity. This is a dangerous loophole that puts the public at massive risk. Most galling is that the government has known about it for years"

       It is not just passports that are destroyed by migrants. Dan O'Mahoney, the Clandestine Channel Threat Commander, told MPs: "Encouraged by the facilitators, [those crossing] will get rid of any sort of documentation or pocket litter, as we call it in law enforcement – phones, SIM cards, anything – before they are intercepted by Border Force."

       The Home Office data show the scale of the problem for the first time. In 2018, just 13 out of 299 (4.34 per cent) migrants arrived with a passport, falling to 1.1 per cent in the first two quarters of last year.

       A Home Office spokesman said: “This Government is reforming our country’s approach to illegal entry to the UK and asylum by making the tough decisions to end the overt exploitation of our laws and UK taxpayers.

       “The Government’s Nationality and Borders Bill will make it a criminal offence to knowingly arrive in the UK illegally and introduce life sentences for those who facilitate illegal entry into the country. We will seek to return people if appropriate even if they do not have official documentation.”