HOME Secretary Amber Rudd has denied the Government are blackmailing the EU, after the letter triggering Article 50 seemed to imply Britain would withhold intelligence about terrorist threats, unless the UK received favourable terms in a trade deal.

In the Prime Minister’s missive to Donald Tusk, she warns of “weakened” security if no agreement can be reached. “The United Kingdom wants to agree with the European Union a deep and special partnership that takes in both economic and security cooperation,” May writes.

“If, however, we leave the European Union without an agreement the default position is that we would have to trade on World Trade Organisation terms. In security terms a failure to reach agreement would mean our cooperation in the fight against crime and terrorism would be weakened.“ Britain is a member of the Five Eyes intelligence alliance, with MI5, MI6 GCHQ sharing data, with security agencies in the USA, Canada, Australia and New Zealand.

Home Secretary Amber Rudd denied the UK were threatening hold back intelligence shared between those countries from the rest of the continent.

She told Sky News: “There is no threat. I’m amazed that is even being thrown up ... The conversations I’ve had with fellow interior ministers [show] we need to have an agreement so that the UK can continue to keep the European continent safe and that the European continent can continue to help keep the UK safe. This is not going to be traded. This is something which needs to be negotiated, because there are different elements to it, that are going to have to be replaced and amended to arrive at that. But there is huge amounts of goodwill.”

However, Rudd added: “If you look at something like Europol, we are the largest contributor to Europol. So if we left Europol, then we would take our information — this is in the legislation — with us. The fact is, the European partners want us to keep our information there because we keep other European countries safe as well.”

Stephen Gethins, the SNP’s Europe spokesman said: “Theresa May desperately needs to start making friends in Europe and she’s beem doing a woeful job so far. The UK need a good deal more from than the EU does, any threats from UK government ministers do no help build alliances.”

Sir Nicholas Macpherson, former Permanent Secretary to the Treasury tweeted: “Crime & terrorism does not respect borders. Not a credible threat to link cooperation to a trade deal. #timetogetreal”

Liberal Democrat leader Tim Farron said: “This letter is a blatant threat. Security cooperation has been lumped together with trade. Utterly scandalous.”

House of Commons Home Affairs Committee chairwoman Yvette Cooper said: “The Prime Minister is right to say that ‘in security terms a failure to reach agreement would mean our co-operation in the fight against crime and terrorism would be weakened’.

“But that means her willingness to walk away with no deal if she does not get the deal she wants would not only be wrong but dangerous. She should not be trying to use this as a bargaining chip in the negotiations.

“This is not a threat to the rest of Europe, it would be a serious act of self-harm.”

Downing Street said: “The Prime Minister’s words speak for themselves: it’s a simple fact that if we leave the EU without a deal then the arrangements which we have as part of our EU membership will lapse.”