The Brexit secretary, Stephen Barclay, has complained to EU ambassadors that Brussels is failing to come up with ideas for replacing the Irish backstop as talks with the bloc became stuck in an “impasse”.

According to a diplomatic cable detailing recent contacts between Barclay and embassies in London, the minister has insisted both the UK and EU have a responsibility to come up with ideas.

Irish PM 'looking forward' to hearing Boris Johnson's Brexit proposals Read more

The approach reflects a nervousness in Downing Street at putting forward any alternatives to the backstop for fear that they will be swiftly shot down, fuelling the febrile political atmosphere in Westminster.

On Wednesday afternoon, Johnson’s envoy to the EU, David Frost, came to Brussels with a team of British officials for his latest round of talks with the commission’s negotiating team but failed to deliver on his previous promise to provide concrete proposals.

“We learnt or got confirmed today what the UK does not want, but what must come instead?” asked one EU source. “Either there is no plan. Or a plan is in gestation. Or there is a plan that the UK government does not want to share yet, beyond some general statements.”

Quick guide What is the Brexit ‘backstop’? Show Hide What is the original ‘backstop’ in the withdrawal agreement? Variously described as an insurance policy or safety net, the backstop is a device in the withdrawal agreement intended to ensure that there will not be a hard border between Northern Ireland and the Republic of Ireland, even if no formal deal can be reached on trade and security arrangements. It would mean that if there were no workable agreement on such matters, Northern Ireland would stay in the customs union and much of the single market, guaranteeing a friction-free border with the Republic. This would keep the Good Friday agreement intact. Both the UK and EU signed up to the basic idea in December 2017 as part of the initial Brexit deal, but there have been disagreements since on how it would work. The DUP have objected to it, as it potentially treats Northern Ireland differently from the rest of the UK, creating a customs divide in the Irish Sea, which is anathema to the unionist party. Hardline Tory Eurosceptics also object to it, as they perceive it to be a trap that could potentially lock the UK into the EU’s customs union permanently if the UK & EU cannot seal a free trade agreement. That would prevent the UK from doing its own free trade deals with nations outside the bloc. What was added to May’s withdrawal agreement? Joint interpretative instrument

A legal add-on to the withdrawal agreement was given to Theresa May in January 2019 to try to get her deal through the UK parliament. It gives legal force to a letter from Jean-Claude Juncker and Donald Tusk, the presidents of the commission and council. This stated the EU’s intention to negotiate an alternative to the backstop so it would not be triggered, or, if it was triggered, to get out of it as quickly as possible. Unilateral statement from the UK This set out the British position that, if the backstop were to become permanent and talks on an alternative were going nowhere, the UK believes it would be able to exit the arrangement. Additional language in political declaration This emphasises the urgency felt on both sides to negotiate an alternative to the backstop, and flesh out what a technological fix would look like. However, it failed to persuade the attorney general, Geoffrey Cox, who said that while it ‘reduces the risk’ of the UK being trapped in a backstop indefinitely, it does not remove it. What happens next? Boris Johnson declared the Northern Ireland backstop ‘dead’ during his leadership campaign, and promised to throw it out of any deal he renegotiated with the EU. The EU has repeatedly stated that it will not reopen the withdrawal agreement for renegotiation. Daniel Boffey, Martin Belam and Peter Walker

Michel Barnier, the EU’s chief negotiator, and the European commission president, Jean-Claude Juncker, have repeatedly said it is for the British government to put forward any alternative arrangement for the backstop given it is a UK request for it to be ditched.

A commission spokeswoman said on Wednesday that Juncker had “recalled” at a meeting of commissioners earlier in the day “that it’s the UK’s responsibility to come forward with concrete proposals that are operational and also compatible with withdrawal agreement”.

The British government insists parliament will not accept a deal that includes the backstop, which entails the whole of the UK, albeit temporarily, staying in a customs union and Northern Ireland remaining in the single market.

On Tuesday, the prime minister told the Commons the government recognised that “for reasons of geography and economics, agri-food is increasingly managed on a common basis across the island of Ireland”.

The comments suggested Johnson was willing to accept what one EU official described as a “lightweight backstop” that would involve checks on agri-goods moving between Northern Ireland and Britain but ensure an open border for those goods on the island of Ireland.

The prime minister is due to meet the Irish taoiseach, Leo Varadkar, on Monday in Dublin, where he will expand on the approach.

But the plan leaves open the question of how non-agricultural goods will be checked in a post-Brexit environment when regulations in the north and south of Ireland diverge.

The European commission is concerned that reliance on technology and the creation of new frontier regulatory areas in which checks would be carried out would fail to live up to the commitments of the Good Friday agreement to protect the all-island economy.

In response to Johnson’s claim that progress is being made in the talks, EU officials have instead warned that the discussions are “going nowhere”, and that the seemingly imminent general election in the UK will bring them to a complete halt.

A UK government spokesman conceded that there was yet to be a meeting of minds in the talks but said the pace of negotiations would be intensified this month.

He said: “The prime minister wants to get a deal and is ready to work in an energetic and determined way to get it done. The prime minister’s sherpa [David Frost] will meet with the A50 taskforce this week and throughout September as talks intensify.

“He will be supported in Brussels by an expert team from across government that have expertise in regulations and customs.

“The team intends to run through a range of issues including the removal of the backstop. The prime minister has been clear that there will be no deal unless the withdrawal agreement is reopened and the backstop taken out.

“Discussions so far have shown that the two sides remain some distance apart on key issues but are willing to work hard to find a way through.”