The Brexit minister Lord Frost and the European Commission vice-president, Maroš Šefčovič, are expected to meet virtually this week to try to break the deadlock over Brexit checks in Northern Ireland. But as the countdown begins to a 30 June ban on the sale of chilled meats, including sausages, from Great Britain in Northern Irish supermarkets, tensions between the EU and Boris Johnson’s government remain heightened. The French junior minister for European affairs, Clément Beaune, said on Monday that the current conflict over Brexit was “a test” for Europe while the EU’s former chief Brexit negotiator, Michel Barnier, warned that the UK had to implement the Northern Ireland protocol. “The United Kingdom needs to pay attention to its reputation. I want Mr Johnson to respect his signature,” he said. Last week Šefčovič accused the UK of not delivering pledges made in March 2020 and in December in relation to many parts of the protocol and warned that “patience was wearing very very thin”. After a weekend war of words at the G7 summit there is no sign of tensions abating with renewed threats of a trade war. “Mr Johnson thinks that you can sign deals with the Europeans and not respect them and that Europe will not react. It is a test for Europe,” Beaune told Europe 1 radio on Monday. “I am telling the British people: [Brexit] commitments must be respected … If it is not the case, retaliatory measures could be taken,” Beaune added. To avert further deterioration in relations both sides have just two weeks to strike a new deal on implementation of the Northern Ireland protocol, with the UK government threatening to delay what it has called a “bonkers” outright ban on the sale of chilled meats including sausages from Great Britain that is due to come into force on 30 June. “There is still time,” said one EU diplomat in relation to talks. A phone or online meeting this week could be followed up by a face to face next week if movement on compromises emerge in the coming days. The standoff comes against a background of continuing political instability in Northern Ireland following the ousting of the DUP leader, Arlene Foster, who resigned as first minister at lunchtime on Monday. A new survey by Queen’s University shows that 74% of Northern Ireland voters want a closer relationship between the UK and the EU. Frost has been called to answer “urgent questions” at the Northern Ireland affairs parliamentary committee on Wednesday. At the same time Ireland is hoping the US administration can continue to exert some influence. Last week it emerged that the foreign affairs minister, Simon Coveney, had asked the US national security adviser, Jake Sullivan, to raise the issue of the instability in Northern Ireland with London during a stopover in Shannon airport. “I spent two hours with him, and an hour of that was talking about Northern Ireland, the polarisation of politics here, the instability here, the frustration, the tension in Northern Ireland, and undoubtedly that message has got back very directly to the White House,” he told RTE. “I think we’re lucky to have that kind of relationship with Washington but United States are also a very close partner of the UK, we know that that’s a very special relationship as well … I hope that that intervention can move this process on because Northern Ireland needs certainty now more than anything else,” he added.