A diplomatic row has broken out after the EU's top official claimed the UK had imposed an "outright ban" on the export of Covid vaccines.
European Council President Charles Michel said it applied to all vaccines and components produced in the UK, reports the BBC.
But Foreign Secretary Dominic Raab has described the suggestion as "completely false".
An EU official has been summoned to the Foreign Office for "further discussions" on the matter.
The argument comes with European leaders under pressure over the slow rollout of Covid-19 vaccines.
In the UK, meanwhile, 22.5 million people - a third of the population - have received their first dose.
In his weekly briefing note, Michel said he was "shocked" to hear the 27-member bloc being accused of "vaccine nationalism" following changes it made to export rules earlier this year.
"Here again, the facts do not lie," he wrote.
"The United Kingdom and the United States have imposed an outright ban on the export of vaccines or vaccine components produced on their territory. But the European Union, the region with the largest vaccine production capacity in the world, has simply put in place a system for controlling the export of doses produced in the EU."
In response, Raab has written to Michel to "set the record straight", saying the "false claim has been repeated at various levels within the EU and the Commission".