The EU’s chief Brexit negotiator has told Boris Johnson to stop “pretending” he is negotiating a Brexit deal, amid concerns that the prime minister is not trying to reach an agreement.

It comes after reports that proposals brought to Brussels by UK negotiators amounted to the old agreement, with the section on the Irish backstop simply crossed out in the text.

Speaking in the European Parliament, Michel Barnier said: “Almost three years after the UK referendum, I don’t think we should be spending time pretending to negotiate. I think we need to move forward with determination.”

Mr Barnier said the EU was “open to any UK proposal and are willing to work day and night towards progress”, adding: “If the UK leaves without a deal, I would recall that these questions don’t just disappear. They have been regulated in the withdrawal agreement, they have been covered – but they still remain. Whether we’re talking about the peace in Ireland, citizens’ rights, budgetary issues, they would all need to be settled.”

Responding to Brexiteers, Mr Barnier added: “Nobody is trying to dodge the decision of a majority of the voters of the UK to leave the EU. Nobody is trying to steal Brexit. Nobody is trying to hold the UK against its will in the EU in the Customs Union or in the Single Market. It’s your responsibility to leave.”

Supreme Court protests: Boris Johnson's prorogation legal or not? Show all 15 1 /15 Supreme Court protests: Boris Johnson's prorogation legal or not? Supreme Court protests: Boris Johnson's prorogation legal or not? Protesters gather outside The Supreme Court ahead of a hearing on the legality of Boris Johnson's proroguing of Parliament Getty Supreme Court protests: Boris Johnson's prorogation legal or not? The supreme court justices will sit as a panel of 11 judges to hear the challenge, brought by campaigner Gina Miller, that the Prime Minister acted unlawfully when he advised the Queen to suspend parliament AP Supreme Court protests: Boris Johnson's prorogation legal or not? A woman protests outside the Supreme Court Reuters Supreme Court protests: Boris Johnson's prorogation legal or not? The PM sent lawmakers home on 9 September until 14 October, just over two weeks before the UK is due to leave the European Union AP Supreme Court protests: Boris Johnson's prorogation legal or not? Gina Miller arriving AP Supreme Court protests: Boris Johnson's prorogation legal or not? People protest outside the Supreme Court Reuters Supreme Court protests: Boris Johnson's prorogation legal or not? Boris Johnson likened himself to the Incredible Hulk days previous as he promised to ignore the Commons legislation ordering him to delay Brexit if negotiations break down PA Supreme Court protests: Boris Johnson's prorogation legal or not? Officials bring in documents Reuters Supreme Court protests: Boris Johnson's prorogation legal or not? Protesters hold banners outside the Supreme Court in London, Tuesday Sept. 17, 2019. The Supreme Court is set to decide whether Prime Minister Boris Johnson broke the law when he suspended Parliament on Sept. 9, sending lawmakers home until Oct. 14 â€” just over two weeks before the U.K. is due to leave the European Union. (AP Photo/Matt Dunham) Matt Dunham AP Supreme Court protests: Boris Johnson's prorogation legal or not? Protesters hold banners outside the Supreme Court in London, Tuesday Sept. 17, 2019. The Supreme Court is set to decide whether Prime Minister Boris Johnson broke the law when he suspended Parliament on Sept. 9, sending lawmakers home until Oct. 14 â€” just over two weeks before the U.K. is due to leave the European Union. (AP Photo/Matt Dunham) Matt Dunham AP Supreme Court protests: Boris Johnson's prorogation legal or not? Protesters hold banners outside the Supreme Court in London, Tuesday Sept. 17, 2019. The Supreme Court is set to decide whether Prime Minister Boris Johnson broke the law when he suspended Parliament on Sept. 9, sending lawmakers home until Oct. 14 â€” just over two weeks before the U.K. is due to leave the European Union. (AP Photo/Matt Dunham) Matt Dunham AP Supreme Court protests: Boris Johnson's prorogation legal or not? People protest outside the Supreme Court of the United Kingdom during a hearing on Prime Minister Boris Johnson's decision to prorogue parliament, in London, Britain September 17, 2019. REUTERS/Phil Noble PHIL NOBLE Reuters Supreme Court protests: Boris Johnson's prorogation legal or not? Protesters hold banners outside the Supreme Court in London, Tuesday Sept. 17, 2019. The Supreme Court is set to decide whether Prime Minister Boris Johnson broke the law when he suspended Parliament on Sept. 9, sending lawmakers home until Oct. 14 â€” just over two weeks before the U.K. is due to leave the European Union. (AP Photo/Matt Dunham) Matt Dunham AP Supreme Court protests: Boris Johnson's prorogation legal or not? Joanna Cherry of the Scottish National Party leaves the Supreme Court Reuters Supreme Court protests: Boris Johnson's prorogation legal or not? Demonstrators protest outside the Supreme court in central London on the first day of the hearing into the decision by the government to prorogue parliament on September 17, 2019. (Photo by Tolga Akmen / AFP)TOLGA AKMEN/AFP/Getty Images TOLGA AKMEN AFP/Getty

The EU has asked the UK to present proposals to replace the Irish backstop, which Mr Johnson says he wants to scrap. But with a 30-day deadline that Mr Johnson set for himself in Berlin almost exhausted, the UK has yet to present anything concrete in writing.

It comes amid reports from the EU side that Mr Johnson experienced a “penny dropping moment” during his meeting with EU boss Jean-Claude Juncker earlier this week.

According to the accounts of EU officials quoted in the Financial Times, Mr Johnson appeared not to understand that his proposals for Northern Ireland to stick to EU food and livestock regulations after Brexit would not resolve the ongoing impasse over customs arrangements at the border.

An official described Mr Johnson “slumping” in his chair at the lunch in Luxembourg, as his Brussels counterparts said that the plan for common “sanitary and phytosanitary” (SPS) rules on the island of Ireland would not do away with the need for customs checks on the vast majority of goods crossing the border.

According to the newspaper, one official said the PM turned to chief negotiator David Frost and Brexit secretary Stephen Barclay and said: “So you’re telling me the SPS plan doesn’t solve the customs problem?”

Speaking in the same European Parliament debate on Wednesday, Jean-Claude Juncker, the European Commission president, said of a meeting with Mr Johnson in Luxembourg on Monday: “I said to prime minister Johnson that I have no emotional attachment to the backstop but I stand by the objectives it’s designed to achieve. I called on the PM to come forward with operational proposals in writing for practical steps which would allow us to achieve those objectives.”

Although it has not presented full proposals, the UK has come forward with one idea: a theoretical veto for Northern Ireland on any backstop replacement. This plan was however dismissed by Guy Verhofstadt on Wednesday as “a permanent instrument for blackmailing” the EU during negotiations.

Mr Verhofstadt, the parliament’s Brexit chief, took the opportunity to round on the decision by the UK government to suspend parliament, telling MEPs: “Jean-Claude Juncker and Donald Tusk can do a lot of things but at least they cannot close the doors of our [parliament].

“If the eurosceptics want to make their ridiculous comparison again to the Soviet Union from now on they can point the finger to Westminster instead of to Strasbourg or Brussels.”

He also warned that the UK would not be allowed to become “a Singapore in the North Sea” after it left, adding “that will not happen”. He also voiced concerns about the EU settlement scheme set up by the UK’s Home Office, telling MEPs: “What we don’t need now is a bureaucratic application – we need the automatic application of all our EU citizens.”

MEPs in the European Parliament are later expected to approve a resolution that says they support an extension of Article 50 to prevent a no-deal Brexit.

The Independent understands that there was controversy on the parliament’s Brexit steering group over whether the resolution should include “preventing a no deal” as one of the possible justifications for an Article 50 extension. Some MEPs on the group – thought to be close to Emmanuel Macron – attempted to have the justification removed, leaving only a general election and second referendum as reasons for a further delay. A source said the thinking behind the attempt to remove the line was that it undermined the EU negotiating position.