EU law strengthens Spanish hand in Gibraltar dispute
Now, with Britain leaving the club and Spain staying in, Madrid has seized the chance to press its case.
"This is an important change in the EU's position on the Gibraltar issue," said Camino Mortera, a senior research fellow at the Centre for European Reform.
"Once the UK leaves the EU, the 27 obviously have to side with the club members, and not with the outgoing side," she told AFP.