Most migrants who entered the UK illegally will be barred from claiming citizenship under new Home Office guidance.

Labour has adopted a principle from previous government legislation barring illegal migrants securing citizenship despite repealing large sections of Rishi Sunak’s 2023 Illegal Migration Act.

The guidance for immigration, entitled Nationality: Good Character Requirement, took effect on Monday and is targeted at migrants crossing the Channel in small boats or sneaking into the UK in lorries.

It comes as Labour comfortably won a second reading vote for its Border Security Bill which introduces counter-terror style measures to smash the people-smuggling gangs including a maximum 10-year jail sentence for possession of boats or equipment that could be used for illegal migration.

The guidance states: “A person who applies for citizenship from 10 February 2025 who has previously arrived without a required valid entry clearance or electronic travel authorisation, having made a dangerous journey will normally be refused citizenship.

“A dangerous journey includes, but is not limited to, travelling by small boat or concealed in a vehicle or other conveyance. It does not include, for example, arrival as a passenger with a commercial airline.”

According to Oxford University’s Migration Observatory, it will affect more than 200,000 people who have refugee status or indefinite leave to remain after seeking asylum if they entered the UK illegally.