The British government changed its travel information for Spain on Wednesday to include a longer list of documents that the Spanish authorities will accept to prove legitimate residency in Spain.
Since Christmas, only Spanish and Andorran nationals plus foreigners with residency can enter from the UK by sea or air. This rule is still in force until at least 2 March.
Spain had been saying only green residency certificates or a plastic TIE card were valid proof of legal residency. But now, for example, an acceptance of residency letter will suffice.
The website of the Spanish Consulate in London has also put up a link to the new advice and the UK government says airlines and travel companies have been informed.