The Home Secretary has slotted in a last-minute change to the Government's immigration bill to allow British terror suspects to be stripped of their citizenship even if it leaves them stateless.
In an apparent effort to appease Conservative backbenchers calling for tougher measures in the new legislation, Theresa May has tabled an amendment which will permit the removal of a UK passport from any suspect whose conduct is " seriously prejudicial to the vital interests of the UK".
The Home Secretary already has the power to take away British citizenship from those with dual nationality, however, this change would allow her to make subjects stateless if the person has been naturalised as a British citizen.
The move is likely to anger human rights campaigners, who have previously likened such at tactic to those used in states such as Zimbabwe, where statelessness has been used to clamp down on political dissent.
It comes as the Home Secretary and Prime Minister David Cameron face a backbench rebellion when the Immigration Bill returns to the Commons tomorrow.
The Home Office insisted powers to make British citizens stateless will be used sparingly and in strict accordance with the UK's international obligations.
Immigration Minister Mark Harper said: " Those who threaten this country's security put us all at risk. This Government will take all necessary steps to protect the public.
"Citizenship is a privilege, not a right. These proposals will strengthen the Home Secretary's powers to ensure that very dangerous individuals can be excluded if it is in the public interest to do so."
One of the most high-profile cases involving statelessness concerns Hilal al-Jedda, who fled from Iraq to the UK in 1992 as a refugee from Saddam Hussein's regime. He won asylum and in 2000 was granted British nationality.
However, he returned to Iraq in 2004 where he came under suspicion of involvement in terrorism and in 2007 was stripped of his British nationality.
Al-Jedda, who now lives in Turkey, has since been fighting against the move through a series of legal appeals.
In October last year, Supreme Court judges ruled that it was illegal to make him stateless.
However, despite this ruling, the Home Secretary stripped al-Jedda of his UK citizenship for a second time in December last year.
A spokesman for legal charity Reprieve said: "This is a very alarming development, which reverses a long-standing ban on citizenship-stripping where doing so would leave someone stateless.
"It would give the Home Secretary the power to tear up people's passports without any need for the kind of due process we might once have expected as British citizens.
"The concern is that this is all part of the wider excesses of the US-led 'war on terror': once someone has been rendered stateless, it becomes much easier to subject them to execution by drone, without the inconvenience of legal consequences."
The Prime Minister has reportedly been seeking to minimise a rebellion by reassuring backbenchers he shares their concerns, but has appealed for them to allow legislation to proceed uninhibited.
Around 70 Conservative backbenchers have signed a tweaked amendment to the legislation, originally tabled by Nigel Mills MP, which calls on the Government to reinstate restrictions on migrants from Romania and Bulgaria working in Britain until the end of 2018.
A further 100 MPs have come out in support of a move by Tory MP Dominic Raab to completely block foreign criminals appealing against deportation by claiming a right to a ''family life'' in the UK. The Bill returns to the Commons tomorrow.
Mr Mills, Conservative MP for Amber Valley, attempted to have labour market restrictions for Romanians and Bulgarians extended before they were lifted on January 1.
The Government has refused repeated demands to publish or commission estimates of the numbers expected to enter Britain in the face of unofficial research predicting as many as 50,000 people arriving from the eastern European countries each year.
Mr Cameron rushed through new measures to ensure EU migrants are unable to claim out-of-work benefits for their first three months in the UK - but this was not enough to satisfy Mr Mills and his backers.
However, Mr Mills has lost the significant support of influential backbencher Douglas Carswell MP, who despite having signed the amendment announced on his blog he would no longer vote for it.
Mr Carswell wrote: ''It is well meaning, but ultimately pointless displacement activity. A kind of Parliamentary grandstanding.''
He added: ''If we want to restrict the free movement of people into Britain from the European Union, then there is only one thing we can do - leave.''
Meanwhile, Mr Raab's amendment would see the Home Secretary - rather than the courts - have the final say on whether an offender's family links are strong enough to allow them to avoid deportation.
Foreign criminals who can prove they face torture, ill-treatment or death in their home country will still be able to overturn deportation orders under separate human rights measures.
More than 200 foreign criminals successfully challenge deportation on human rights grounds every year with around 90% relying on the ''right to private and family life'' set out under Article 8 of the European Convention on Human Rights.
It is understood Tory whips are trying to persuade backbenchers to back amendments tabled by Stephen Phillips MP, which give the Home Secretary a duty to assess whether EU immigration is excessive and to assess the effects of new countries joining the EU.
Speaking at Prime Minister's Questions, Mr Cameron signalled that he shared backbenchers' frustration with the use of Article 8 and urged them not to delay the passage of the Bill.
He said: ''We need to correct - and we will correct in the Immigration Bill - the fact that it is so difficult to deport people who don't have a right to be here and should be facing trial overseas or should be deported overseas but make spurious arguments about the right to a family life.
''It is right that we are changing that. There is nothing anti-European about it. It's a very sensible step that this Government is taking and we should pass the Immigration Bill with all speed.''