Spain's Foreign Minister Alfonso Dastis said on Monday that he was a little surprised by the tone coming out of Britain over Gibraltar and called for calm.
"The Spanish government is a little surprised by the tone of comments coming out of Britain, a country known for its composure," Dastis said during a conference in Madrid.
A former leader of UK Prime Minister Theresa May's Conservative party, Michael Howard, said she would even be prepared to go to war to defend the territory, as Britain did with Argentina over the Falkland Islands 35 years ago.
The future of Gibraltar, a rocky British outpost on Spain's southern tip, has become the first major dispute of the exit negotiations since Prime Minister Theresa May filed the formal divorce papers on March 29.
The European Union proposed on Friday offering Spain a right of veto over Gibraltar's future trade relations with the bloc.
Gibraltar scolds EU
Gibraltar's leader scolded EU Council President Donald Tusk on Monday for giving Spain a right of veto over the future relationship between the British enclave and the European Union after Britain leaves the bloc.
According to the EU's draft joint position on the exit talks, "after the United Kingdom leaves the Union, no agreement between the EU and the United Kingdom may apply to the territory of Gibraltar without the agreement between the Kingdom of Spain and the United Kingdom".
"Mr Tusk, who has been given to using the analogies of the divorce and divorce petition, is behaving like a cuckolded husband who is taking it out on the children ," Gibraltar's Chief Minister Fabian Picardo said in an interview.
Picardo said Spain was trying to bully Gibraltar and that the EU was allowing the bullying to happen. He said the British Overseas Territory would not allow itself to become a bargaining chip in the Brexit negotiations.
Britain will wait for EU guidelines
Britain will wait until the end of the month to find out what guidelines the other members of the European Union have agreed regarding issues such as Gibraltar, May's spokesman said on Monday.
"These are draft guidelines that were issued ... We will wait and see what is agreed by the 27 (EU countries), " the spokesman told reporters.
Britain's Brexit minister David Davis held a "friendly and constructive" meeting with Spain's Dastis in Madrid on Monday as part of a pre-arranged visit, the spokesman added, during which he raised the issue of Gibraltar.
On Howard's comments, the spokesman said what Howard "was trying to establish was the resolve that we will have to protect the rights of Gibraltar and its sovereignty".
Asked if that would include ultimately sending a naval task force to protect Gibraltar as Britain did to the Falklands, he said: "That isn't going to happen."