The president of the European Commission José Manuel Barroso has spoken on the phone with Spain's Prime Minister Mariano Rajoy about the tensions over Gibraltar:
They agreed that a Commission fact finding mission should as soon as possible examine in loco the border control/movement of people and goods questions.
President Barroso expressed his hope that Spain and the UK will address these matters in a way that is in line with their common membership in the EU.
It may be a pre-planned training exercise but what timing: UK warships sail through disputed water to Her Majesty's naval base on Gibraltar.
Spain could damage to the economy in Gibraltar, but in doing so it would harm its own, so a further escalation of threats is unlikely.
The PM has said he is seriously concerned by Spain's plans to introduce a levy at the border with Gibraltar.