Paris attacks: David Cameron warns UK terrorist attack is 'highly likely'

David Cameron placed the UK on high alert for a terror attack, as holidaymakers in Paris were told to “stay indoors” and security checks were ramped up at British airports and ferry terminals.

The Prime Minister said the scale of the atrocity in France revealed “a greater ambition for mass-casualty attacks” on the West, and warned that an attempt to bring terror to the UK was “highly likely”.

Mr Cameron said the public should be “alert but not alarmed” and vowed to “wipe out” the so-called Islamic State (Isis) and its ideology.

It comes as the PM prepares to hold crunch talks on the growing terror threat with Russia’s president, Vladimir Putin, at the G20 summit in Turkey on 16 November.

Downing Street said the meeting would be the first time the pair had met for face-to-face discussions in more than a year and provided an opportunity for a “hard-headed engagement” over the threat posed by IS.

Sources close to the PM insisted there was no change in the Government’s position on air strikes in Syria – which have been ruled out until “political consensus” can be reached – and said his immediate focus was on checking for British casualties and reviewing security in the light of the attacks in France.

The scale of the terrorist threat to Britain was underlined after Downing Street took the rare step of briefing Labour leader Jeremy Corbyn following a meeting of the Government’s emergency Cobra committee early on 14 November.

In a statement on 14 November Mr Corbyn condemned the attack as “horrific and immoral”, but reiterated his opposition to any military response.

“It’s vital at a time of such tragedy and outrage not to be drawn into responses which feed a cycle of violence and hatred,” he said.

Mr Corbyn also confirmed he had scrapped a controversial speech, which he had been set to deliver on 14 November, in which he would have suggested that British bombing operations against IS in Iraq had contributed to the increased terror threat. Extracts from the speech released in advance indicated he would have used his strongest language yet to criticise the UK’s involvement in the fight against IS.

In the speech to Labour’s East of England conference he was expected to say: “For the past 14 years, Britain has been at the centre of a succession of disastrous wars that have brought devastation to large parts of the wider Middle East.

“They have increased, not diminished, the threats to our own national security in the process.”

Mr Corbyn was last night also facing scrutiny over his links to the controversial Stop the War Coalition, after the group released an inflammatory statement blaming the West for the French attacks, titled “Paris reaps whirlwind of Western support for extremist violence in Middle East”. Until September Mr Corbyn was the chair of the Stop the War group.

The anti-war group’s statement said: “Without decades of intervention by the US and its allies there would have been no ‘war on terror’ and no terrorist attacks in Paris.”

Jamie Reed, the Labour MP for Copeland, said the remarks exposed the group’s “despicable idiocy”.

Hilary Benn, the Shadow Foreign Secretary, added: “I don’t agree with [Stop the War’s] analysis at all and I think we should just all remember the 16 or so British citizens who lost their lives in the attack on the twin towers in New York on the 11th of September 2001. That’s prior to the action that was taken in Afghanistan and the events subsequently.”

Mr Benn said IS represented an ideology “fundamentally opposed to our values and our way of life”: “That is why there is such a broad measure of agreement across the world that Isil/Daesh presents a serious, present and real threat to all of us and we have to do all we can to combat all of that.”

As a measure of respect, Downing Street lowered the Union flag to half-mast and flew it alongside the French tricolore. Speaking from No 10, Mr Cameron condemned the “horrifying and sickening attack” on Paris.

“Our hearts go out to the French people, and to all those who lost loved ones,” he said. “The British and French people stand together, as we have so often before in our history when confronted by evil.”

He said Britain’s message to the French people was simple: “We stand with you, united.”

Mr Cameron said the victims were “simply going about their way of life”, adding: “They were killed and injured by brutal, callous murderers who want to destroy everything our two countries stand for: peace, tolerance, liberty.”

But, Mr Cameron added, “We will not let them. We will redouble our efforts to wipe out this poisonous, extremist ideology and, together with the French and our allies around the world, stand up for all we believe in.”

The PM said the police and security services would review their anti-terror plans in the wake of the Paris attacks.

But he also warned that “we must recognise that however strong we are, however much we prepare, we in the UK face the same threat. That’s why we continue to encourage the public to remain vigilant”.

He finished his statement with a message to the French public that their fight against IS was also “our fight” and pledged to “defeat these terrorists”.

The Foreign Office have updated its travel advice, urging Britons in Paris to “exercise caution in public places” and pointed to the French government’s call for people to “stay indoors”.

The Queen sent her condolences to the French people, telling President François Hollande that she and the Duke of Edinburgh were “deeply shocked and saddened by the terrible loss of life”.

•A major airport security alert was sparked early on 14 November after a French man was discovered with a gun trying to catch a flight.

Police were called to Gatwick airport, West Sussex, at 9.30am, following what they described as “suspicious actions by a man who discarded an item at the airport”.

The 41-year-old was questioned by police and the airport’s North Terminal was evacuated for six hours while bomb-disposal specialists were called in to carry out a “small controlled explosion”.