Nigel Farage has put mass deportations at the centre of his new immigration plan — promising to detain and remove hundreds of thousands of asylum seekers from the UK.

While Reform UK currently has only four MPs, polling suggests they could win the next election and be in a position to implement this.

It's a striking escalation in the rhetoric around immigration — raising the question of whether this marks a turning point in British politics.

Has anything like this been attempted before, is it even possible, and how does it fit into the long, often heated history of immigration policy in the UK?

On this episode of The Fourcast, Cathy Newman is joined by Jacqueline McKenzie, a partner at the human rights law firm Leigh Day who specialises in immigration and asylum cases, and journalist and author David Goodhart who is the head of demography, immigration and integration at the Policy Exchange think tank.