Relations between the European Union and the United Kingdom have recently deteriorated. The EU envoy in London was summoned on Wednesday to clarify comments that Britain had issued a vaccine export ban, causing another diplomatic snafu.

The UK was so enraged by European Council President Charles Michel’s statement on Tuesday that Britain had “put an absolute ban on the export of vaccines” that it summoned the ambassador for a morning meeting.

According to a statement from the British government, the country “has not blocked the export of a single COVID-19 vaccine.” Any claims of a UK export ban or vaccine restrictions are absolutely false.”

The spat comes as the COVID-19 vaccination campaign in the United Kingdom is hailed as a massive success, although the EU’s 27-nation bloc sees it as a big disappointment. The UK has vaccinated about 35% of its adults, while the EU has only vaccinated 9.5 percent of its adults.

Already uncomfortable bedfellows during the United Kingdom’s 47 years of EU membership, things have become increasingly worse after the United Kingdom voted to leave the bloc in 2016. The split became official last year after acrimonious exit negotiations, but both sides soon began arguing over a trade deal.

On Christmas Eve, an agreement was reached, but it still needs to be ratified by the European Parliament. In the meantime, both sides are arguing for everything from the EU’s diplomatic position in London to the import-export regime.

The EU is seeking legal action against the United Kingdom for failing to adhere to the withdrawal deal that underpins the Brexit divorce. Meanwhile, Britain has declined to give full diplomatic status to the EU’s first-ever ambassador to the region. The EU, according to London, is an entity, not a nation.

The EU quickly seized on the topic, claiming that the ambassador would be unable to attend the Wednesday morning meeting due to the ongoing legal battle over his position. Instead, the EU dispatched a lower-ranking representative.

Michel, on the other hand, declined to retract his remarks and maintained that any ban could take several forms. He tweeted, “Different ways of enforcing bans or limits on vaccines/medicines.” “It would be great if the UK response leads to increased transparency and exports to the EU and third countries.”

Even if the United States has its own ban, Peter Liese, a German member of the European Parliament and one of the key parliamentary experts on the subject, said Wednesday that the situation in the United Kingdom is “even worse” because “significant quantities of the AstraZeneca vaccine went from the continent to the U.K.”

“For example, from the Dessau IDT Biologika plant in Dessau, Germany, and the company is still not ready to offer vaccine that is manufactured in the United Kingdom to supply the European Union,” he claimed. AstraZeneca has denied syphoning off vaccines intended for the EU and sending them to other countries.