Police and immigration authorities will be handed new powers to stop suspected spies and agents at the UK border in the wake of the Salisbury nerve agent attack.
The crackdown aims to bolster Britain’s defences against so-called “hostile state activity” by giving officers anti-terror style powers to intercept individuals who may pose a threat as they arrive in the country.
Details of the regime emerged as ministers unveiled a wide-ranging new Counter-Terrorism and Border Security Bill.
Currently police and immigration personnel can question and detain people entering and leaving the country through sea ports, airports and international rail stations.
But they can only deploy the powers in cases where they are seeking to establish whether the subject appears to be concerned in the commission, preparation or instigation of acts of terrorism.
For the purposes of the new power, a hostile act is defined as one that “threatens national security, threatens the economic well-being of the UK, or is an act of serious crime” and is linked to a foreign state.
Plans for the measure were first announced by Theresa May in the aftermath of the attempted assassination of former double agent Sergei Skripal and his daughter Yulia in March.
The Government has accused Russia of being behind the attack, but Moscow has repeatedly denied responsibility.
Publishing the new Bill, Home Secretary Sajid Javid said: “We judge that it was highly likely that the Russian State carried out the appalling attack in Salisbury which demonstrates why the police need robust powers to investigate, identify and challenge those acting against our interests.
“This is a necessary and proportionate response to the threat and will, of course, be subject to strict safeguards and robust oversight to assure its proper use.”
Home Office documents published alongside the proposed legislation state the UK faces a “sustained threat” from hostile state actors “seeking to undermine our national security in a wide variety of ways, including espionage and – as the attack in Salisbury has made clear – violence against individuals”.
The ability to stop, question, search and detain individuals to determine whether they appear to be or have engaged in hostile activity represents a “major improvement” in the UK’s ability to tackle the threat, according to the department.
Schedule 7 of the Terrorism Act 2000 allows officers to examine a person at a port area when they are entering or leaving the country. Last year 16,349 people were examined under the provision in Britain.
A Government impact assessment on the proposed hostile activity power says it is expected annual use will be “very low” and “far below” the level of Schedule 7 activity.
“It is further expected that the rate of non-compliance will be low,” the document adds.
Oversight of the power will be assigned to the Investigatory Powers Commissioner, and the Bill includes provisions for safeguards to protect legally privileged and journalistic material.
They were admitted to Salisbury District Hospital, along with Detective Sergeant Nick Bailey. All three have since been discharged.
On Tuesday Scotland Yard disclosed that police are still following a “number of lines of inquiry” as part of a huge investigation to establish who carried out the poisoning.