Shabana Mahmood should ignore Labour backbenchers’ views on illegal immigration and “press ahead” with policies to make it harder for migrants to permanently settle in the UK, a former Labour home secretary has said.

Alan Johnson said the Home Secretary would “always get a kickback” from Labour MPs on efforts to clamp down on illegal migration, but “the more she listens to her backbenchers, the worse it’ll be”.

Mahmood is trying to push through a raft of measures aimed at tightening up the immigration system, including making most immigrants wait at least 10, rather than five, years for indefinite leave to remain (ILR) and applying it retrospectively to people already in the UK. For refugees, it could take 20 years.

The Home Secretary wants to follow Denmark in making refugee status temporary, with asylum seekers’ cases reviewed every 30 months and individuals returned to their country of origin if it is deemed to have become safe for them.

The Immigration and Asylum Bill, which is currently moving through Parliament, would also change how human rights and modern slavery laws are applied to asylum applications to combat what the Home Office describes as “vexatious” claims.