The EU’s chief negotiator Michel Barnier said that they still needed to hear more from the UK side about its proposals for replacing the Northern Ireland backstop.

Addressing MEPs, Barnier said: “The position of the European Union has never been an ideological one. It has always been a pragmatic one.

“The new UK Government this week in Luxembourg outlined the aspects of the backstop they don’t like. That is not enough, however, to move towards achieving a solution,” he said.

“We need a legally operative solution in the Withdrawal Agreement which addresses each one of the risks created by Brexit.”

European Commission president Jean-Claude Juncker said there was a “palpable” risk of a no-deal Brexit and progress on replacing the backstop could not be made to reach a deal until the UK submitted written proposals.

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Speaking at the European Parliament following his meeting with Boris Johnson earlier this week, he said “the risk of a no-deal remains real” but that would be the choice of the UK Government.

“I said to Prime Minister Johnson that I have no emotional attachment to the safety net, to the backstop, but I stated that I stand by the objectives that it is designed to achieve. 

“That is why I called on the Prime Minister to come forward with operational proposals, in writing, for practical steps which would allow us to achieve those objectives.

“Until such time as those proposals have been presented, I will not be able to tell you, looking you straight in the eye, that any real progress has been achieved.”

Mr Juncker told MEPs that his talks with Mr Johnson had been “friendly, constructive and in part positive”.

“The Commission is prepared to work day in day out, morning until night – with a few breaks – to try to find the technical and political solutions we need but I am not sure that we will get there,” he said.

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“There is very little time remaining but what I do know is that we have to keep trying.”

Finnish European affairs minister Tytti Tuppurainen added: “The latest developments in Westminster and the call for a further extension make it very difficult to predict how things will unfold.

“We have to acknowledge that, currently, a no-deal on October 31 is a quite likely outcome.”

 The warning comes after Poland’s ambassador to the UK, who has written a letter to 800,000 Poles advising them to “seriously consider” returning to their home country, has said he is concerned about the settled-status application process.

Speaking on BBC Radio 4’s Today Programme, Arkady Rzegocki said of the procedure: “It is straightforward but we are concerned about this process a little.