BRITAIN’S security chiefs are preparing themselves for Russian retaliation in the wake of the Syrian military strikes, which could involve ministers, MPs and other high-profile public figures being targeted with personally embarrassing claims.

Theresa May is said to have received risk assessments from MI6, which pointed to Kremlin-backed hackers releasing compromising material – “kompromat” – against some of her Cabinet colleagues.

Britain’s cyber-intelligence agency, GCHQ, and the Ministry of Defence are believed to be on standby to retaliate “proportionately” with cyber-experts having already “pre-positioned” within the computer networks of Russian targets should Moscow target critical facilities such as the National Grid and the NHS, both of which are on high alert for cyber-intrusions.

One security source explained: “We know what’s in the Russian playbook – kompromat-type material - we’re all prepared for that.

“We know that they do have that ability to penetrate at that scale. We’re not saying that there’s a picture of ‘X’ that’s waiting to come out but it’ll be amazing to us if they don’t have some of that kind of material.”

Another intelligence figure warned: “It wouldn’t be impossible that they get through in some way that really hurts us. If they aggressively come after us, we will certainly have the ability to do some stuff to them. But unlike Russia, we abide by the law, so anything we do would be proportionately done.”

Asked if he was worried about cyber revenge attacks, Boris Johnson said: “We have to take every possible precaution and when you look at what Russia has done, not just in this country in Salisbury but the attacks on TV stations, on the democratic processes, on the critical national infrastructure, of course, we have to be very, very cautious indeed.

“But I want to stress…we in the UK do not seek an escalation; absolutely not. That was why it was so important to get our message over to Russia, over to everybody involved that our response is limited to saying no to chemical weapons,” added the Foreign Secretary.

Meanwhile in New York, Nikki Haley, the US Ambassador to the United Nations, announced that America would impose new sanctions on Russia in the wake of the chemical weapons attack on Douma.

"Russia sanctions will be coming down. Secretary Mnuchin will be announcing those on Monday if he hasn't already and they will be going directly to any sort of companies that were dealing with equipment related to Assad and chemical weapons use," Ms Haley told CBS.

"So, everyone is going to be feeling it at this point. Everyone knows that we sent a strong message and our hope is that they listen to us," she added.

Elsewhere, Mrs May told The Sunday Times that the UK Government would target the cronies of Vladimir Putin, who had “illicit finances” in London.

“We are looking at every aspect of the action that can be taken,” she said.

A No 10 source added: “You are going to see extensive action on financial measures against Russian oligarchs in the UK shortly.”

Earlier this year, Ben Wallace, the Security Minister, warned that those people using Britain as a haven for ill-gotten gains would be the target of new unexplained wealth orders[UWOs], which came into effect in January.

These enable the Government to seize property if individuals are unable to explain how they acquired assets of more than £50,000.

While UWOs can apply to all nationalities, it is thought Russians are now expected to be a specific target.

Last month, UK ministers signalled that the Government intends to ban Scotland's secret tax haven firms, so-called Scottish Limited Partnerships, in a crackdown on the laundering of Russian dirty money; sparked by the Salisbury poisoning.

Their move comes after constructive pressure from the Scottish Government and a Westminster campaign led by the SNP as well as a three-year campaign of investigative journalism from The Herald.

This newspaper has repeatedly exposed the use of the Scottish-based shell companies to move money anonymously through offshore tax havens and has highlighted concerns that the Russian President and his associates could be using them to bypass Western sanctions.