Gibraltar will not tolerate being a bargaining chip and will not be the victim of Brexit negotiations, the British territory's Chief Minister has said.
Fabian Picardo called on EU leaders to remove references to the territory from draft Brexit guidelines, and said Spain is bullying Gibraltar and the EU is allowing it to act in this way.
Mr Picardo continued that European Council President Donald Tusk is behaving like a "cuckolded husband who is taking it out on the children" by allowing Spain to include a reference to Gibraltar in the Brexit guidelines.
The row over Gibraltar erupted on Friday after a paragraph in the European Council's guidelines for Brexit negotiations appeared to offer Spain a veto on the territory's future.
The guidelines published by Council president Donald Tusk state that after Brexit, no agreement between the EU and the UK will apply to Gibraltar unless agreed by Madrid.
The dispute then intensified after former Tory leader Lord Howard appeared to suggest Theresa May would be prepared to go to war over the British territory.
Spain's foreign minister responded by saying that there was no need for countries to lose their tempers over Gibraltar.
Alfonso Dastis continued that he was a "little surprised" at the tone of discussion coming from the UK since it is a country "traditionally characterised by its composure".
Following the UK's Brexit vote, Mr Dastis said: "The Spanish Government does not have to answer to every politician's statement in the United Kingdom about this issue.
"The Spanish government is a little surprised by the tone that has been created in the United Kingdom, a country traditionally characterised by its composure.
"But it's obvious that in this case [Europe and Gibraltar], the traditional 'British phlegm' has been notable for its absence."
When questioned on Monday if she would rule out war with Spain, the Prime Minister laughed and said that instead the UK would simply be talking to the EU member.
She continued that Brexit negotiations would include all 27 EU member states and she would attempt to get the best deal for the UK and Spain.
Ms May also said she had spoken to Mr Picardo and made Britain's support for Gibraltar clear to him, adding that the UK's position has not changed and she will work to get the best deal in Brexit negotiations.
Ms May previously vowed not to trade away the Rock's sovereignty in pursuit of a trade deal with the EU as the UK withdraws from the bloc.
Foreign Secretary Boris Johnson added: "The position of the Government is very, very clear, which is that the sovereignty of Gibraltar is unchanged and it is not going to change and cannot conceivably change without the express support and consent of the people of the Gibraltar and the United Kingdom, and that is not going change."
Speaking in Luxembourg at a meeting of EU foreign ministers on Monday, Mr Johnson's Dutch counterpart said that the issues surrounding the sovereignty of Gibraltar shows just "how difficult the divorce" between the UK and the EU has become.
Bert Koenders also urged parties to avoid inflaming the situation, urging the countries involved to "be cool and carry on, and not use too harsh language".
Spain has a long-standing territorial claim on Gibraltar, which has been held by the UK since 1713 and currently has the status of British Overseas Territory.
Gibraltar's 30,000 inhabitants voted overwhelmingly in favour of remaining in the EU in the referendum – 96% wanted to stay – and the territory is also home to important UK military bases.