Russia has launched a “dirty tricks” campaign against Britain and the US in the wake of the Syria airstrikes as Boris Johnson warned of the need to be prepared for retaliatory attacks.
Whitehall sources on Sunday night confirmed a Pentagon analysis that showed a 20-fold increase in Russian-sourced “disinformation” being spread online since the cruise missile attacks on Syria in the early hours of Saturday.
There are fears that it could be a precursor to a campaign of cyber attacks by the Kremlin, and the Foreign Secretary said Britain must take “every possible precaution” to guard against it.
It comes as Jeremy Corbyn attempts to force a Commons vote on Syria that could make it harder for the Prime Minister to mobilise the Armed Forces without the permission of MPs.
Mr Corbyn will on Monday ask the Speaker to grant an emergency debate that is likely to lead to a vote which will scrutinise Mrs May’s judgement in authorising the airstrikes.
Mrs May will instead tell the Commons on Monday that bombing Syria was in Britain’s “national interest” to prevent future chemical attacks “within Syria, on the streets of the UK or elsewhere” as she invokes the Salisbury poisonings as justification for the UK’s participation in the US-led strikes.
She will also say that “it was the right thing to do” to avert further suffering caused by chemical attacks and that “we are not alone - there is broad-based international support for the action we have taken”.
Russia, which backs the Assad regime in Syria, had repeatedly warned in the build-up to the cruise missile strikes that there would be consequences if they went ahead, and Mr Johnson told the BBC’s Andrew Marr that Russia “gives us every possible signal and evidence that we have to beware”.
Asked if he was worried about cyber attacks on the NHS, the National Grid and other infrastructure, he said: “I think 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.”
The Pentagon said there had been a surge in Russian “troll” accounts promoting false claims about the missile attacks, including that 70 per cent of the missiles had been shot down.
Pentagon spokesman Dana White said: “The Russian disinformation campaign has already begun. There has been a 2,000 per cent increase in Russian trolls in the last 24 hours.”
A Whitehall source said Russia was engaging in a “dirty tricks” campaign, while Government sources said officials would be analysing Kremlin-linked social media “bot” accounts in the coming days to assess the extent to which Britain had been targeted by them.
There were, however, genuine questions about whether the attack by 105 American, British and French cruise missiles had obliterated Assad’s chemical weapons capabilities or not.
Brigadier-General Zaher al-Sakat, who served as head of chemical warfare in the powerful 5th Division of the Syrian military until he defected in 2013, said the most strategic sites - including a depot called Taqsis in the central province of Homs - were not hit in Saturday’s strikes.
He said: “Taqsis depot is what we wanted to be hit. As long as it’s still functioning then they’ll still have chemical weapons and the ability to produce more.”
The applications for emergency debates will be made under Standing Order 24 of the Commons rules, and while they do not result in binding votes any defeat for Mrs May over Syria would weaken her politically and make it harder in future to take military action without the backing of MPs.
Several Tories have already said they believe Mrs May should have put the matter to a vote, increasing the danger of a defeat for the Government.
Meanwhile French President Emmanuel Macron said he had convinced Mr Trump to maintain troops in Syria, as he defended France's participation in joint air strikes.
In telephone calls before the Saturday airstrikes, Mr Macron said he had persuaded the American president to commit to the long term. "We convinced him it was necessary to remain there," he said.