FILE PHOTO: Sir Richard Dearlove, Master of Pembroke College, Cambridge; former Chief, British Secret Intelligence Service (MI6) takes part in the panel discussion "Global Risk" at the 2011 The Milken Institute Global Conference in Beverly Hills, California May 3, 2011. REUTERS/Lucy Nicholson

LONDON (Reuters) - Two Brexit-supporting former British defence chiefs have said that Prime Minister Theresa May’s European Union withdrawal agreement will threaten national security if it is passed by members of parliament next week, Sky News reported on Thursday.

May’s spokeswoman said the comments by former Chief of the Secret Intelligence Service Richard Dearlove and the former Chief of Defence Staff Charles Guthrie were “completely wrong”.

In a letter to chairmen of May’s Conservative Party local associations, Dearlove and Guthrie warned that her Brexit agreement would “threaten the national security of the country in fundamental ways”.

“Buried in the 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,” said the letter, which Sky News published on its website.

Both Dearlove and Guthrie supported Brexit ahead of the 2016 referendum in which Britain voted to leave, arguing that quitting the EU would be better for Britain’s defence and security.

“Please ensure that your MP (Member of Parliament) votes against this bad agreement and supports a sovereign Brexit on WTO rules,” their letter said.

Asked about the letter’s claim, May’s spokeswoman said: “Nothing in the Withdrawal Agreement or Political Declaration cuts across NATO, our defence and intelligence relationship with the USA or the five-eyes alliance (with Canada, Australia, New Zealand and the United States). In fact our deal delivers the broadest security agreement the EU has with any of its partners.”

In November, Britain’s Security Minister Ben Wallace said leaving the EU without a deal would jeopardise cooperation with the bloc and affect the ability to keep the public safe.

“If we reject the current deal and go back to square one, this will open the door to far greater uncertainty, increased risk and the prospect of downgrading our ability to protect the public,” he said.