A key Angela Merkel ally in the European Parliament held meetings with Theresa May and David Davis and said he is “more optimistic” about the possibility of reaching agreement with the UK than before.

Manfred Weber, who is leader of Angela Merkel’s party’s group in the European Parliament, told reporters after a fifty minute meeting with the Prime Minister and Brexit Secretary David Davis: “I am one of the more sceptical partners from the European side toward the Brexit process, but my main message is that I am more optimistic.”

Mr Weber praised Theresa May’s speech at the Lord Mayor’s Banquet on Monday, where she was heavily critical of Russia’s attempts to interfere in elections in Europe and America.

“I want to thank her because that was clearly a message that shows us that we have still a lot of common interests, and common threats ahead of us, and that is why it is important to work together.”

But Mr Weber added that Theresa May was aware that Brexit “is difficult and will cause damage".

He said that the UK is “leaving the club” and would have to “pay its open bill.”

Any Brexit deal has to be ratified by the European Parliament, and Mr Weber made clear that there are limits to what the UK can achieve.

“I cannot accept a treaty where a member state outside of the European Union will have the same benefits as being inside the European Union,” he said. “That must be clear for everybody. When you are leaving the European Union, you are losing some of the benefits.”

He said Brexit was counter to everything that the EU had been trying to achieve for forty years, which the UK had until recently supported.

“The whole idea of building up the European Union, which was supported by the British governments, the idea was to make the lives of European citizens better. We are destroying some of the things that we achieved already.