Theresa May has been accused of trying to shamefully blackmail the EU just hours after formally triggering the process of Brexit.

The accusations came as Angela Merkel also dealt an early blow to the PM’s Brexit plans in the opening salvos of what is set to be two years of bitter negotiations.

Soon after Article 50 was triggered, thereby starting the clock on the UK’s divorce from the EU, the German Chancellor dismissed the possibility of trade talks taking place at the same time as negotiations for the withdrawal – something Mrs May has consistently requested as being key to Britain securing the best deal possible.

In the letter formally triggering Article 50, which was received by European Council President Donald Tusk today, Mrs May made clear her desire that the two issues should be discussed at the same time.

The letter reads: “The United Kingdom wants to agree with the European Union a deep and special partnership that takes in both economic and security cooperation. To achieve this, we believe it is necessary to agree the terms of our future partnership alongside those of our withdrawal from the EU.”

It continues: “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. In this kind of scenario, both the United Kingdom and the European Union would of course cope with the change, but it is not the outcome that either side should seek. We must therefore work hard to avoid that outcome.

In response, Ms Merkel made it clear that the terms of any divorce between the UK and EU must be finalised before any discussions can take place on trade.

She said on Wednesday afternoon: “The negotiations must first clarify how we will disentangle our interlinked relationship. Only when this question is dealt with, can we… begin talking about our future relationship.”

Mrs May’s letter to Mr Tusk also drew an angry response from some quarters of the EU, who interpreted it as a threat to the security of the continent. One source told the Guardian it was nothing short of an attempt at “blackmail”.

Tim Farron, the Lib Dem leader, branded it shameful:

“It is shameful that Theresa May has threatened to withdraw security co-operation from our closest neighbours and allies. With growing terrorist threats from around the world, it is imperative that we work together with European allies for our mutual security. She is prepared to put the safety of British and European citizens on the line just so she can deliver her hard Brexit.

“Security is too important to be used as a bargaining chip and this will backfire in any negotiations.”

As the historic letter was delivered to Brussels, Europe started saying its goodbyes.

Mr Tusk told a press conference: “There’s no reason to pretend this is a happy day – neither in Brussels or London.

View photos European Council president Donald Tusk said he would miss the UK (Rex) More

“There is nothing to win in this process and I am talking about both sides. In essence, this is about damage control.”

And in a personal message to the UK, Mr Tusk added: “We already miss you. Thank you and goodbye.”

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View photos Theresa May signed the Article 50 letter last night (Getty) More

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