Reform UK would create an ICE-style agency dedicated to deporting hundreds of thousands of people, as well as terminating the status of those with indefinite leave to remain (ILR), the party will say.

It would also ban the conversion of churches into mosques and fund a radical expansion of stop and search, the party’s new home affairs spokesperson, Zia Yusuf, will also say in a speech on Monday. The deradicalisation programme Prevent would also have its mandate redrawn to focus on Islamist extremism.

Labour said the plans were divisive and showed that Reform was planning “to deport people who have followed the rules, worked hard and built their lives here – our friends, neighbours and colleagues”.

The Labour party’s chair, Anna Turley, said the policies were “a direct attack on settled families and fundamentally un-British”. She added: “Britain is a proud, tolerant and diverse nation, which stands in opposition to the kind of divisive politics stoked by Reform.”

Yusuf will say in a speech that Reform would leave the European convention on human rights (ECHR) and put a legal duty on the home secretary to remove illegal migrants.

He will promise to create a new agency – UK Deportation Command – with the capacity to detain 24,000 migrants at a time and deport up to 288,000 annually on five flights a day. Experts have previously said the costs of such an expansion would be considerable – as of April 2024 there were approximately 2,500 detention spaces.

“For decades, the Tories and Labour have turned the other way while the very fabric of our society has been under assault,” Yusuf will say. “The social contract has not merely been broken; it’s been shattered. Under a Reform government, His Majesty’s parliament will be sovereign once again.

“We will secure our borders, leave the ECHR, and deport those here illegally. My message to the British people is simple: I will secure our borders and make you feel safe.”

In the speech, Yusuf will explicitly blame the former prime minister Boris Johnson for the increase in net migration, saying the Conservative leader “threw open our borders” and that granting ILR would mean “a lifetime of living off the British taxpayer” because of new access to benefits.

ILR holders make up only about 2.7% of all universal credit claimants, with at least a third of those in employment.

ILR would be scrapped under Reform and replaced with a renewable five-year work visa with a high salary threshold, Yusuf will say, meaning tens of thousands currently with settled status could lose their right to be in the UK.

Labour has also proposed changing ILR, with new conditions. The home secretary, Shabana Mahmood, has said the party plans to increase the period of eligibility from five years to 10 years.

Yusuf will also propose a new approach to knife crime and policing, saying he would end any diversity initiatives in police forces and expand stop and search powers.

“I will take a zero-tolerance approach to Islamist extremism,” Yusuf will say, promising to overhaul Prevent and proscribe the Muslim Brotherhood organisation.

“We will protect British culture, because a nation without a culture is not a nation at all. It is just an economic zone. We will preserve Britain’s Christian heritage and end the incendiary practice of converting churches into mosques or any other place of worship.”