British Foreign Secretary Dominic Raab lashed out at the European Union’s plan for a post-Brexit deal for Gibraltar, accusing the bloc of trying to undermine the U.K.’s “sovereignty” over the territory.

Raab said the EU’s draft negotiating mandate was no basis for talks over a long-term solution for the small stretch of land adjoining Spain’s southern tip. The EU’s proposal “directly conflicts” with a temporary agreement struck last year, he said.

It “cannot form a basis for negotiations,” Raab said in an emailed statement Tuesday. “We have consistently showed pragmatism and flexibility in the search for arrangements that work for all sides, and we are disappointed that this has not been reciprocated. We urge the EU to think again.”

The question of Gibraltar’s future relationship with the EU is fraught with political tensions. The territory has been under British control since 1713 but is contested by Spain. Pedro Sanchez, the Spanish premier, has previously attempted to use Brexit as a way to ramp up pressure for talks over the future sovereignty of the British Overseas Territory.

Inflamed Relations

The Gibraltar dispute is the latest in a succession of arguments that have flared up between London and Brussels since the U.K. completed its separation from the political bloc at the start of the year.

Spain and the U.K. sealed a last-minute accord on Dec. 31 to avoid stricter controls on the movement of people and goods to the territory. Under a four-year implementation period, they agreed that officials from the European border agency Frontex would assist with controls at the port and airport.

Commission Vice President Maros Sefcovic said the proposal for the mandate honors “the political commitment we made to Spain to start the negotiations of a separate agreement between the EU and the U.K. on Gibraltar.”

The British government objects to a string of proposals and inferences contained in the draft EU mandate.

According to a person familiar with the matter, the U.K. believes the EU has abandoned its commitment for Frontex to operate controls in the territory, opening the way for Spanish authorities to conduct border checks instead. That would be unacceptable to both the governments of the U.K. and Gibraltar, the person said.

The U.K. is also concerned about Spanish authorities holding exclusive competence for short-term visas for people entering the bloc’s border-free Schengen area through Gibraltar. British officials also object to proposals for applying EU law, including allowing Spanish police to cross the border, as well as on market regulations and customs rules.

No Barriers

According to directives published by the European Commission, the EU’s executive arm, the bloc wants a deal that aims to scrap all current physical barriers between Gibraltar and the Schengen area for the circulation of people.

The recommendation “is without prejudice to the issues of sovereignty and jurisdiction, and focuses on cooperation in the region,” the Commission said in the statement.

The proposed negotiating directives include rules establishing responsibility for asylum, returns, visas, residence permits, and operational police cooperation and information exchange.

Other measures affect areas such as land and air transport, the rights of cross-border workers, the environment, financial support, and establishing a level playing field.

Under the proposal, parties could review implementation of an agreement after four years, terminate it at any time, and unilaterally suspend its application in limited cases.