Theresa May has told the new prime minister of Spain that she will “engage constructively” over the impact of Brexit on Gibraltar.
The PM raised the issue during a telephone call to congratulate socialist Pedro Sanchez, who was sworn in after ousting conservative Mariano Rajoy.
Gibraltar is part of the single market but not the customs union, and voted overwhelmingly for Britain to remain part of the European Union.
The referendum result sparked debate over the future of the territory, with Spain declaring hours later that the “Spanish flag on the Rock is much closer than it was before”.
Mr Sanchez toppled Mr Rajoy after a court ruling in a major corruption case involving the conservative leader’s Popular Party.
A Downing Street spokesman said: “The Prime Minister congratulated Prime Minister Sanchez on his new role, noting that Spain was a close ally and that we shared a long history of friendship and co-operation.
“She said we look forward to continuing our work together across the full range of our common interests and objectives, including our close security co-operation and commercial ties.
“The Prime Minister paid tribute to the Spanish victim of last year’s London Bridge attack, Ignacio Echeverria. They agreed that his efforts to save others during the attack were truly heroic.
“The Prime Minister said the UK was leaving the EU but not Europe, and our relationships with the EU and member states would always be extremely important to us.
“They agreed on the importance of protecting the rights of Spanish people in the UK as well as the many UK citizens in Spain.
“On Gibraltar, the Prime Minister said the UK would continue to engage constructively with the Government of Gibraltar and the Spanish to address issues arising from the UK’s withdrawal from the EU.
“They looked forward to meeting at the June European Council.”