Russia has developed the capacity to cripple Britain with cyber-attacks, a military intelligence chief warned last night.

Sir Chris Deverell said Kremlin agents could shut down power supplies, hijack air traffic control and even disable air conditioning.

The general, who oversees the UK's military intelligence, cyber and special forces, said Moscow 'did not care' about civilian lives.

His warning came after it emerged that a policeman who dealt with the poison attack on a Russian double agent in Salisbury is in intensive care. Scotland Yard said a nerve agent was used in what is seen as a Kremlin-backed attempt to assassinate Sergei Skripal.

Aides confirmed Prince William will not attend this summer's World Cup in Russia after Whitehall sources said it clearly appeared to be a 'state-backed attack'. Colonel Skripal, 66, and his daughter Yulia, 33, are fighting for their lives following the poison attack.

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Sir Chris Deverell (pictured) said Kremlin agents could shut down power supplies, hijack air traffic control and even disable air conditioning

Sergei Skripal (left, in 2006) and his daughter Yulia (right) are fighting for their lives after they were 'targeted' with a deadly substance in the middle of Salisbury town centre

After it emerged that the spy may have been targeted because he was still 'active' and had been briefing MI6:

Vladimir Putin warned Russia's enemies would be 'served with poison';

Boris Johnson said the UK would respond robustly if a Moscow link was proven;

Scotland Yard appealed for witnesses to Sunday's attack;

Fresh doubts were raised over the deaths of Col Skripal's relatives;

Speaking at a new cyber school at Shrivenham defence academy in Wiltshire yesterday, General Deverell said there was 'no limit' to President Putin's methods of attack.

'What they seek to do is to steal, plant, manipulate, distort, destroy our information,' he said. 'It's part of their doctrine.

'Every single system we have in our lives is in some way controlled by systems that have ones and noughts in them. If you can get them then you can affect us.

'That would stretch to power, it would stretch to traffic systems, it would stretch to air traffic control systems, it would stretch to air conditioning systems, it would stretch to just about anything you can imagine.

'In doing that it could have very, very serious consequences for a lot of people.

Metrpolitan Police Assistant Commissioner Mark Rowley (pictured) confirmed a nerve agent was used to target Sergei Skripal in Salisbury

'Do we believe they are capable of it? Yes. Have we seen other things being done that are damaging? Yes. They being Russia.'

Asked why Moscow would want to carry out such attacks, he replied: 'They care only about what is in the interests of their elites. They don't care about innocent people going about their lives. They are quite honestly capable of anything.'

General Deverell said Britain had previously named Russia as being behind cyber-attacks and the death of Alexander Litvinenko, the former KGB spy who was killed in London in 2006.

Armed forces minister Mark Lancaster said the most serious cyber-attacks would be classed as the equivalent of a military strike and would lead to retaliation.

'Our Government, are industries and our businesses are regularly targeted by criminals and foreign intelligence services seeking to disrupt, corrupts and steal,' he said yesterday.

'And this threat is evolving and growing, cyber is now a critical part of the arsenals of our enemies, whether those enemies are terrorists, criminals or state actors.'

General Deverell said Britain had previously named Russia as being behind cyber-attacks and the death of Alexander Litvinenko (pictured), the former KGB spy who was killed in London in 2006

He said the UK was engaged in offensive cyber-attacks too against national enemies: 'A capability that not only seeks out attackers but attributes and punishes, this is not science fiction not some vague cinematic future, we are already using cyber techniques every day in fighting what remains of Islamic State.

'Now we must show that we can adapt, that means attracting the brightest and best and giving them the best possible training and preparation as our cyber warriors.' General Deverell delivered his warning as he announced the creation of an elite team of cyber warriors, who will be on standby around the clock to tackle computer attacks.

'Our threat-hunters give us the ability to identify, isolate and respond to these threats, whenever and wherever they might arise,' he said.

Sir Chris, who is head of the Joint Forces Command, said the control units inside many buildings were vulnerable: 'Those are unsophisticated devices. Most of them were designed before the cyber threat was really perceived and some of them are connected to the internet. They are vulnerable to attack.

'The impact of these things we utterly take for granted in our normal lives being switched on or switched off.

'There is no limit to the potential vectors of attack.'

He said it would be hard to prove a link between the Salisbury attack and the Kremlin.