The UK's House of Lords has approved a controversial law allowing the government to strip citizenship from naturalised Britons it accuses of terrorism.

In April, the upper house of the British parliament had rejected the measure proposed by Theresa May, the UK's interior minister, but passed the law on Monday after a government amendment.

Members of the house voted 286 to 193 in favour of the amended legislation, peers from the opposition Labour party voted against.

The lords reversed course after May accepted the addition of a clause that would only allow citizenship to be taken away if there were "reasonable grounds" to believe suspects could acquire another nationality.

Campaign groups have slammed the law, saying it would leave people stateless and offered no safeguards against abuse.

Liberty, a British civil-rights campaign group, criticised the House of Lords for their "empty compromise" and described the proposals as "barbaric".

A statement by the group said the only way to challenge government decisions on stripping citizenship would be through "a secretive, one-sided procedure".

The government has said the proposals were brought in to defend the public from "dangerous individuals", the AFP news agency reported.

Under previous legislation, the home secretary was able to withdraw citizenship from British people who carried dual nationality.