A former top spook and an ex-defence chief have taken the unprecedented step of urging Tory constituency bosses to order their MP to vote against Theresa May's Brexit deal.

Former MI6 head Sir Richard Dearlove and ex-former chief of the defence staff Lord Guthrie have written to Conservative association chairs claiming the EU withdrawal agreement threatens national security.

In an explosive move which will infuriate the prime minister and her allies, delight Brexiteers and dismay Remainers, they write: "Please ensure that your MP does not vote for this bad agreement."

In their letter, Sir Richard - who was chief of the secret intelligence staff - and Lord Guthrie claim the prime minister's Brexit deal would surrender the UK's forces and intelligence services to EU control.

They also protest that it would damage the UK's relationship with NATO, the US, and the leading Commonwealth security and intelligence partners Canada, Australia and New Zealand.


The controversial move follows a similar warning on security six weeks ago.

Image: Theresa May is grappling to get her Brexit deal through parliament

On 29 November, Sir Richard, along with pro-Brexit campaigners Sir Rocco Forte, Martin Howe QC, Lord Lawson, Lord Trimble and former Royal Marines chief Major General Julian Thomspon, wrote to the prime minister.

At the time, Downing Street said the claims that Mrs May's deal would threaten UK national security and surrender influence on defence and intelligence to the European Union were "simply wrong".

"The deal provides a feasible framework for times of crisis," said a Number 10 spokesman at the time.

"It gives us an option to co-operate in these areas. It does not create an obligation to do so."

But that rebuff has prompted Sir Richard and Lord Guthrie to claim the first letter "touched a raw nerve" in Number 10 and write to Tory association chairs urging them to put pressure on Conservative MPs.

In response to the latest letter, a Number 10 spokeswoman said: "The claim is completely wrong. Nothing in the Withdrawal Agreement or our Political Declaration cuts across Nato, our defence or intelligence relationship with the USA or with the Five Eyes alliance.

"In fact, our deal delivers the broadest security agreement the EU has with any of its partners."

In their letter, Sir Richard and Lord Guthrie write: "Your MP will shortly be called upon to support the Prime Minister's Withdrawal Agreement.

Image: MPs are due to vote on the withdrawal agreement on Tuesday

"As a former Chief of the Intelligence Service, with my colleague Lord Guthrie, who served as chief of the Defence Staff shortly before I was in charge of MI6, we are taking the unprecedented step of writing to all Conservative Party chairmen to advise and to warn you that this Withdrawal Agreement, if not defeated, will threaten the national security of the country In fundamental ways.

"Please ensure that your MP does not vote for this bad agreement."

Explaining why they oppose the new relationship with the EU in the agreement, they write: "Buried in this Agreement is the offer of a 'new, deep and special relationship' with the EU in defence, security and intelligence which cuts across the three fundamentals of our national security policy: membership of NATO, our close bilateral defence and intelligence relationship with the USA and the Five Eyes intelligence alliance."

The Five Eyes Alliance is a group of Western intelligence sharing nations made up of the UK, US, Canada, Australia and New Zealand. Intelligence gathered by one of these countries is shared with all the others.

The letter concludes: "The first duty of the state, above trade, is the security of its citizens.

"The Withdrawal Agreement abrogates this fundamental contract and would place control of aspects of our national security in foreign hands.

"Please ensure that your MP votes against this bad agreement and supports a sovereign Brexit on WTO rules, without payment of ransom."

Labour's shadow Cabinet Office minister Jo Platt thanked Sir Richard for highlighting "the dangers of Theresa May's deal with regards to national security".

"Theresa's flimsy negotiations with regards to our national security aren't good enough, it's something we need concrete reassurances on and we haven't got that with this deal," she told Sky News.

"Theresa May has had two years to negotiate a deal on our national security and she hasn't done that.

"If there's anything the Labour Party would have done it, it would have been to secure something as serious as our national security."

Labour Stephen Doughty MP, a member of the Home Affairs Committee and supporter of the People's Vote campaign, said: "Sir Richard Dearlove is right that the deal is a bad one for our security, but his proposed solution of leaving the EU without any agreement at all would make things even worse.

"As members of the EU we have the European Arrest Warrant available to arrest and extradite terrorism and serious crime suspects, and we have full access to the key databases on crime suspects across Europe that are accessed thousands of times every day by British police forces.

"As soon as we leave the European Arrest Warrant will be weakened as Germany, at the very least, will be constitutionally bound to opt out of extraditions to Britain and we have no long-term guarantee of access to the security data we rely on.

"No one voted to weaken the fight against terrorism or serious crime and this is another reason we need a People's Vote and the option of keeping all our rights as full members of the EU."

Liberal Democrat MP Tom Brake MP said: "It's astonishing that someone of Sir Richard Dearlove's experience can make the case that cutting our ties with the EU would enhance security cooperation. It clearly wouldn't.

"We've already lost access to the Galileo programme and police departments around the country have time and again warned about the threat Brexit poses to their ability to stop terrorists.

"Then again, this is the guy who was head of intelligence when we went into Iraq."

The intervention comes just days before MPs are due to vote on Mrs May's divorce deal, next Tuesday.

The UK is due to leave the EU on 29 March 2019, by default.

Mrs May is grappling to get her Brexit deal through parliament, trying to win over the more than 90 Conservative MPs who vowed to vote against it in December.