The former head of MI6 has warned the Prime Minister's Brexit deal will threaten "national security" and must be "defeated".
In a letter sent to Conservative associations, Sir Richard Dearlove urged MPs not to back the controversial deal, which will be voted on in Parliament next Tuesday.
He claims the Withdrawal Agreement as it stands places aspects of the UK's security in "foreign hands".
The letter urges association chairs to "ensure that your MP votes against this bad agreement".
It also appears to endorse a no-deal Brexit, by encouraging recipients to support leaving the EU on "World Trade Organisation rules", which will happen by default if no agreement is secured with the EU before March 29.
It isn't the first time Sir Richard has spoken out against the Brexit deal, warning that if passed through Parliament it would "threaten Western security" in November last year.