The home secretary, Sajid Javid, is taking the UK down a “very dangerous road” with plans to expand powers to strip dual citizens of their British citizenship, a leading human rights group has warned.

Suspected terrorists have previously had their UK citizenship taken away – most often while they are abroad – and the move does not require prior approval from a judge or parliament.

In his speech at the Conservative party conference, Javid proposed extending the reach of the power to cover serious criminals, citing child grooming gangmasters as an example.

Corey Stoughton, acting director of Liberty, the human rights and civil liberties group, said: “The home secretary is taking us down a very dangerous road. Few will sympathise with the people this power has been used against – but making our criminals someone else’s problem is not responsible, effective policymaking. It’s the government washing its hands of its responsibilities.

“Accepting citizenship stripping as a legitimate punishment could see us all sleepwalking into a future where the list of ‘serious’ crimes gets ever longer and the government uses this extreme measure more and more frequently. Banishment belongs in the dark ages and has no place in the UK in 2018.”

From 2010 to 2015, 33 people were stripped of their British citizenship, all of them dual nationals, on terrorism grounds. Figures for 2015 onward have not been made available.

Javid has made tackling child sexual exploitation a key issue for his department. He recently announced an extra £21.5m to help investigators who say they are facing a “constant uphill struggle” to track down offenders.

A Home Office spokesperson said: “Any British citizen may be deprived of his or her citizenship if the secretary of state is satisfied that it would be conducive to the public good. It is a power used for extreme and exceptional cases.

The Guardian view on Javid and Johnson: what’s the Conservative future? | Editorial Read more

“Deprivation on conducive grounds can be used where individuals pose a threat to national security, or have been involved in war crimes, serious and organised crime and unacceptable behaviours such as extremism or glorification of terrorism.”

Diane Abbott, the shadow home secretary, said citizenship stripping was discriminatory against minority communities. “Stripping dual nationals of British citizenship is inherently discriminatory and risks creating yet another ‘hostile environment’ not for illegality but for Britain’s many minority communities,” she said.

“The Conservatives’ inability to learn from past mistakes beggars belief, even when mealy mouthed apologies are barely dry on the page. Why not punish Britons according to their crimes rather than their origins?”

In his conference speech, Javid said: “The home secretary has the power to strip dual citizens of their British citizenship. It is a power used for extreme and exceptional cases. It should be used with great care and discretion – but also determination.

“In recent years we have exercised this power for terrorists who are a threat to the country. Now, for the first time, I will apply this power to some of those who are convicted of the most grave criminal offences. This applies to some of the despicable men involved in gang-based child sexual exploitation.”