Spain has abandoned plans to stop an independent Scotland from joining the EU amid an escalating row with Britain over the future of Gibraltar.

Alfonso Dastis, the Spanish foreign minister, said his Government will not block a future Scottish EU membership bid, giving a boost to Nicola Sturgeon.

It came as Sir Michael Fallon, the Defence Secretary, suggetsed that Britain is ready to go to war to defend the sovereignty of Gibraltar. He vowed to go “all the way” to protect the territory.