Downing Street says prime minister is seriously concerned by growing tension over British overseas territory
Diplomatic relations between Britain and Spain have come under further strain after Downing Street said David Cameron was seriously concerned about events on the Spanish border with Gibraltar.
The comments came as Gibraltar's chief minister accused Spain of acting like North Korea after the country's foreign minister suggested introducing a €50 (£43) border fee for vehicles entering or leaving the Rock as part of a long-running dispute over territorial waters.
A No 10 spokesman said the Foreign Office was urgently seeking clarification of reports in the media about the possibility of the Spanish government imposing fees or closing air space. The PM's spokesman said the plans had not been directly raised with the UK government.
"Specifically on this issue of border fees, the Spanish have not raised the prospect of introducing border fees with us. We are seeking an explanation from them regarding reports that they might target Gibraltar with further measures."
The government is in close contact with the Spanish about the issue, but the spokesman refused to give further details about what the next steps might be.
No 10 seems to believe the sabre rattling over border fees may prove to be theatrical. The EU has been trying to settle the dispute over fishing rights, but is not expecting a breakthrough in the short term.
The dispute may ultimately turn on whether the UK is willing to take Spain to court to clarify the legal position on sovereignty of waters.
Cameron last spoke to his counterpart, Mariano Rajoy, about the issue at a European council meeting in June, before the latest escalation of tensions at the border. On Friday last week, William Hague, the foreign secretary raised concerns about delays at the border, with the Spanish ambassador to the UK.
Gibraltar's chief minister, Fabian Picardo, said the Spanish foreign minister, José Manuel García-Margallo y Marfil, was being belligerent when he suggested that a €50 fee could be imposed on every vehicle entering or leaving the British Mediterranean outpost through its border with Spain.
García-Margallo said the proceeds could be used to help Spanish fishermen who have lost out because of damage to fishing grounds allegedly caused by Gibraltarian authorities. Such a fee could impose punitive costs on Gibraltarians who regularly commute to Spain to work.
Picardo said hell will freeze over before the authorities in Gibraltar remove an artificial reef which Madrid claims is harming Spanish fishermen. He said any border costs would violate EU freedom of movement rules.
Spain is also considering closing its airspace to flights heading to the Rock. Picardo claimed such a move would be dangerous, and was the "politics of madness".
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 García-Margallo has said are more reminiscent of the type of statement you'd hear from North Korea than from an EU partner.
"We've seen it before during Franco's time during the 1960s but I think all of us hoped that those politics were never going to come back and that the much more enlightened politics of Mr [Miguel Ángel] Moratinos, who was the previous but one foreign minister of Spain, would prevail, which talked about people working together and creating economic benefits for the citizens on both sides of the frontier rather than the belligerence we are seeing now."
Shadow Foreign Office minister Kerry McCarthy described Spain's proposal to impose a border fee as unacceptable and said the Foreign Office should strongly reject it. She said: "Time and again, the Spanish government has triggered unnecessary delays and disruption to people trying to cross the border between Spain and Gibraltar.
"Now they appear to be using the prospect of a transit fee as a bargaining chip with the UK. This is simply unacceptable. At this time of year many of those people trying to cross the border are British holidaymakers and their families. It is wrong for the Spanish government to attempt to use the border crossing to score political points at their expense.
"Gibraltar's residents also make heavy use of the border crossing to reach their jobs and relatives in Spain. Any measure designed to penalise the residents of Gibraltar should be strongly rejected by the Foreign Office."
On Sunday, the Foreign Office voiced concerns over García-Margallo's comments and said Britain would not compromise its sovereignty over Gibraltar.
A spokesman made clear that the UK expected Madrid to live up to the commitments it made in the 2006 Cordoba agreement, which included deals on issues such as border crossings and flight access, as well as establishing a tripartite forum for regular dialogue between Britain, Spain and Gibraltar.
Spain claims sovereignty over the Rock, which stands on the southernmost tip of the Iberian peninsula but has been a British overseas territory since the treaty of Utrecht in 1713. The British government has made clear that it will not negotiate over sovereignty as long as Gibraltar's people want to remain British.
