A Spanish gunship has made an illegal incursion into British waters off Gibraltar amid rising Brexit tensions over the territory.

Gibraltar's government said the ship entered territorial waters on Tuesday.

A Foreign Office spokesman said: "The Royal Navy challenges all unlawful maritime incursions into British Gibraltar Territorial Waters - and did so again on this occasion."

But a spokesman for Spain's foreign ministry denied the claim, saying the ship was in fact in Spain's own territorial waters.

It comes a day after Spanish foreign minister Alfonso Dastis told the UK not to "lose tempers" after the EU Brexit negotiation guidelines effectively gave Spain significant power over Gibraltar's future.


At the weekend, former Conservative leader Lord Howard told Sky News Theresa May could be willing to defend the British territory, as Margaret Thatcher did over the Falklands.

Illegal incursion into #British #Gibraltar Territorial Waters by Spanish Navy patrol ship Infanta Cristina this afternoon. #BGTW pic.twitter.com/IkYadi8XNn — HM Govt of Gibraltar (@GibraltarGov) April 4, 2017

The Royal Navy told the ship to leave but the incident, the seventh of its kind this year, is likely to escalate already rising tensions over the sovereignty of the Rock.

Theresa May and Foreign Secretary Boris Johnson have moved to reassure the people of Gibraltar that the territory will remain under British control.

Lord Howard told the Sophy Ridge on Sunday programme: "I think there's no question whatever that our government will stand by Gibraltar."

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He said: "Thirty-five years ago this week, another woman prime minister sent a task force half way across the world to defend the freedom of another small group of British people against another Spanish-speaking country.

"I'm absolutely certain that our current prime minister will show the same resolve in standing by the people of Gibraltar."

Downing Street said it would not be sending a task force to Gibraltar but did not condemn Lord Howard's comments.

A spokesman said on Monday: "All that Lord Howard was trying to establish is the resolve that we will have to protect the rights of Gibraltar and its sovereignty."

Spain has a long-standing territorial claim on Gibraltar, which has been held by the UK since 1713 and has the status of a British overseas territory.