Police reviewing security of defected Russian spies in UK after Salisbury nerve agent attack

Sir Mark Sedwill says investigators have not yet identified the culprits

Police are reviewing the security of all defected Russian spies living in the UK in the wake of the attack on Sergei Skripal, officials have revealed.

Sir Mark Sedwill, the national security adviser, said investigators have not yet identified who poisoned the former double agent and his daughter with nerve agent in Salisbury.

“The police who are responsible for protective security and the various agencies alongside them are reviewing the security of all people who might be vulnerable,” he told the Defence Committee.

Asked whether those responsible for the attack on Mr Skripal and his daughter Yulia had been identified, he replied: “Not yet, no.”

But Sir Mark insisted that authorities had acted “much faster” than following the murder of another former Russian spy, Alexander Litvinenko, with radioactive polonium in 2006.

Mr Skripal, a 66-year-old former military intelligence colonel, had been living openly under his real name after being handed over in a 2010 spy swap and the attempted assassination increased fears held by other defectors.

Little over a week after the attack in Salisbury on 4 March, Russian businessman Nikolai Glushkov was found strangled at his London home.

Nikolai Glushkov, a businessman convicted of fraud in Russia, was murdered in his London home (PA/Metropolitan Police)

No one has been arrested in relation to his death and police investigations continue.

Scotland Yard said there was no immediate evidence of a link to the attack on Mr Skripal, but Mr Glushkov’s links to Russian dissident Boris Berezovsky sparked fresh scrutiny over a string of suspicious deaths.

Sir Mark told MPs that Russia posed a wider “existential threat” to the UK, both through its nuclear capability and unconventional warfare.

“What we’ve seen is more aggressive Russian behaviour, the development of hybrid warfare, and upgrades to their conventional military capabilities – some of them designed to threaten our own deterrent that quite rightly means we’re shifting the focus of defence,” he said.

“As we’ve seen most acutely in Salisbury, but with a range of other activities both in the UK and elsewhere, there is very aggressive cyber activity, subversion, money flowing into politics, information operations etc, the Russians are operating aggressively just below the level of armed conflict and that affects our national security.”

He was grilled for more than two and a half hours on Britain’s defence capability.

Several MPs have called for the UK to increase security funding and modify plans originally drawn up several years ago in light of the changing threats posed by cyber attacks, hybrid warfare and terrorist groups such as Isis.

Sir Mark told the Defence Committee spending was already increasing year on year and was above Nato’s benchmark of 2 per cent of GDP, saying allies should increase their own contribution.

“Nato needs to spend more on defence – it’s not just the UK up against Russia, it’s Nato that’s the lynchpin of our defence,” he added.

“I’m not arguing for or against increase in defence budget.”

There has been heavy criticism over delays to the F-35 aircraft programme and new aircraft carriers, with Sir Mark admitting the ships will have to be escorted in contested waters by other countries’ assets.

He insisted the UK was still a “major player” in terms of global military capability, despite “eye-watering” gaps between what the Ministry of Defence wants to buy and can afford.

Sir Mark admitted that there were areas he would personally like to invest in but refused to name them or be drawn on whether he had discussed extra cash with Theresa May.

“There are areas of vulnerability across the entire national security architecture, not just in government, a lot of this is outside government as well,” he said.

“Given the nature of modern warfare and the nature of non-state threats... yes I would like to invest.”

The grilling came after Gavin Williamson, the defence secretary, called on people from technology and communications professions to join the UK’s reserve forces to help combat disinformation campaigns.

In an interview with The House magazine, he said that army recruitment should be about “looking to different people who maybe think, as a journalist: ‘What are my skills in terms of how are they relevant to the armed forces?’

“They are more relevant today than anything else, having those skills, whether it be journalists, those people with amazing cyber and IT skills, those people with the ability to really understand about getting messages across.”