Britain has sparked a post-Brexit spat with the European Union by declining to grant the bloc’s first-ever ambassador to the country full diplomatic status.

Joao Vale de Almeida is the 27-nation EU’s envoy to the U.K., which left the bloc last year. But the British government says the EU is an international organization, rather than a country, and has not given Vale de Almeida the full rights accorded to ambassadors under the Vienna Convention, including immunity from taxation and prosecution.

The EU says the rest of its 143 delegations around the world have all been given full diplomatic status.

“The EU’s status in external relations and its subsequent diplomatic status is amply recognized by countries and international organisations around the world, and we expect the United Kingdom to treat the EU Delegation accordingly and without delay,” European Commission spokesman Peter Stano said Thursday.

Britain’s Foreign Office did not immediately respond to a request for comment.

Prime Minister Boris Johnson’s spokesman, Jamie Davies, said everyone in the EU delegation would get “the privileges and immunities necessary to allow them to carry out their work,” though he did not say whether that amounted to full diplomatic status.

He said the Foreign Office “continue(s) to engage with the EU on the long-term arrangements for the EU delegation in the U.K., and I’m not going to pre-empt the outcome.”

Tobias Ellwood, a lawmaker with the governing Conservative Party who heads Parliament’s Foreign Affairs Committee, said the government was being “petty.”

“We are better than this,” he said.