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 USA, and the leading Commonwealth security and intelligence partners Canada, Australia and New Zealand.
The controversial move, which will be attacked by pro-Remain MPs as inappropriate meddling by a former spook and defence chief in the democratic process, follows a similar warning on security six weeks ago. 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 chair urging them to put pressure on Conservative MPs.