Senior Government officials will face a grilling by MPs on Thursday over record numbers of migrants crossing the Channel to reach the UK.
At least 409 people reached British shores in a rush of small boats on Wednesday, a new single-day record.
It brings the total number of migrants who have crossed the sea to the UK in 2020 to more than 5,600, analysis by the PA news agency shows.
The increasing number of arrivals has led to an inquiry by the Home Affairs Select Committee, who will hear from Home Office and National Crime Agency leaders on immigration enforcement measures on Thursday morning.
Among those appearing is NCA director of threat leadership Robert Jones and former Royal Marine Dan O’Mahoney, who was appointed “clandestine Channel threat commander” by Home Secretary Priti Patel last month.
It comes after a range of measures have been taken to try to prevent people reaching Britain via the Channel such as using Army drones and other armed forces aircraft, including Atlas A-400M, Shadow R1 and P-8 Poseidon, to help monitor Channel crossings.
Meanwhile, the Royal Navy is considering deploying small patrol boats to the Channel to assist Border Force teams.
Think tank IPPR has also criticised the Government’s “hostile environment” deterrent policy, claiming it has failed due to “systematic flaws” in its approach.
It criticised policies it said were intended to encourage people living in the UK without immigration status to leave voluntarily by making it harder for them to get jobs, rent property, open bank accounts, and access welfare and other vital public services.
The think tank’s analysis suggested that the number of voluntary returns which were independent of Home Office involvement has fallen since 2014, when most of the policies were introduced.
Around 12,000 more people without immigration status were independently voluntarily leaving the UK in 2012 than they were in 2018, said the IPPR.
Wednesday’s record total surpasses the previous high of 235, set on August 6.
Earlier in the day, Prime Minister Boris Johnson told Parliament that the UK is a “target and magnet” for people traffickers and vowed to change the law to help tackle the crisis.
Large numbers of migrants were seen being brought into Dover throughout Wednesday, packed aboard Border Force patrol vessels and sitting on the front of lifeboats.
Numbers arriving were so high that dozens of migrants spent an hour sat on Border Force boats in the harbour before they were allowed to disembark.
Meanwhile, empty dinghy after empty dinghy were towed in from the Channel.
In recent weeks, the Home Office has sought to blame French authorities and “activist lawyers” for rising numbers of crossings and difficulties removing asylum seekers once they arrive in Britain.