Gibraltar's chief minister has accused Spain of acting like North Korea and sabre-rattling over the country's new hard-line stance on Gibraltar.
Fabian Picardo said Spanish foreign minister Jose Garcia-Margallo was being belligerent when he suggested that a 50 euro (£43.40) fee could be imposed on vehicles entering or leaving its border with the British Mediterranean outpost.
He told the BBC Radio 4 Today programme: "What we have seen this weekend is sabre-rattling of the sort that we haven't seen for some time.
"The things that Mr Garcia-Margallo has said are more reminiscent of the type of statement you'd hear from North Korea than from an EU partner."
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.