The Government is looking at options for legal action against Spain over the imposition of additional border checks with Gibraltar, Downing Street has announced.
Royal Navy warships have set sail for the Mediterranean as part of a naval exercise which will see the frigate HMS Westminster dock in Gibraltar amid the diplomatic tensions with Spain.
Defence officials have stressed the deployment has long been scheduled and is unrelated to the ongoing issue over the British territory.
Spanish defence minister, Pedro Morenes, has said that it is "totally normal" for British warships to dock in Gibraltar in what is a "routine visit", according to reports.
Mr Morenes reportedly told the Europa Press news agency: "Neither the British nor the Spanish government have an interest in there being bad relations."
He also said that aircraft carrier HMS Illustrious had requested and been granted permission to stop off at the southern Spanish naval base of Rota on August 18, proving that there was no military escalation between the two countries.
Royal Navy warships will set sail for the Mediterranean today amid continued diplomatic tensions with the Spain over the British territory Gibraltar.
The frigate HMS Westminster will dock in Gibraltar as part of the exercise, while other ships in the task group expected to visit Spanish ports.
The vessels, which include helicopter carrier HMS Illustrious, will be taking part in what defence officials stressed was a long-scheduled deployment codenamed Cougar '13 in the Mediterranean and the Gulf.
Alistair Burt MP, Foreign & Commonwealth Office Parliamentary Under Secretary of State, rebutted comments made by Spanish officials, who claimed that the row over Gibraltar could be escalated to the United Nations.
Mr Burt said the United Kingdom was very confident that "self determination matters to the UN" as much as "territorial integrity".
He added: "We are confident, firstly of the support of the people of Gibraltar, who want to remain British. We are confident of our legal position, and you always judge friends by the company they keep."
The Spanish Government is considering raising the future of Gibraltars sovereignty with the United Nations reports the Spanish newspaper El Pais.
It's understood that officials will seek support from Argentina who dispute Britain's claims of sovereignty over the Falkland Islands.
The Spanish Foreign Minister Jose Manuel Garcia-Margallo is expected to visit Argentina in September to discuss the issue further reports the paper.
Gibraltar's government has reportedly said delays at the border with Spain has affected thousands of people, according to a statement reported by the BBC.
It reportedly said: "The Spanish Government has inflicted these unnecessary delays on the elderly, children and the infirm in up to 30 degrees of heat.
"This torture has resulted in an ambulance being deployed to treat people with medical conditions.
"On Friday, for instance, a Spanish man had to be taken to hospital with chest pains."
This video uploaded to You Tube appears to show slow-moving traffic at the border checkpoint between Gibraltar and Spain as cars are searched by officials last Friday.
– A Foreign Office spokesman
We are aware and very concerned about events at the Spain/Gibraltar border.
Over the weekend, our Ambassador in Madrid has raised our concerns with the Spanish Deputy Foreign Minister and we have registered our protest with the Spanish Ambassador in London.
The Foreign Secretary has also called the Spanish Foreign Minister Garcia-Margallo this evening to express our serious concerns and to urge a speedy resolution to the problems at the border.
The Foreign Secretary William Hague has put pressure on Spain over claims it is deliberately engineering lengthy delays at the border with Gibraltar.
In a telephone call with his Spanish counterpart, Garcia Margallo, Mr Hague raised "serious concerns" over severe delays caused when officials carried out intensive vehicle searches.
Thousands of cars leaving the British territory were stopped for checks causing six hour traffic jams in the searing heat.
Gibraltar's government accused Spain of "torture" by inflicting searches on vulnerable passengers and causing "unnecessary delays".
Mr Hague has used British diplomatic channels to make Britain's concerns of the dispute known over the weekend but tonight moved to intervene directly.