Downing Street has hit out at the EU for describing Gibraltar as a UK “colony”, branding the wording "completely unacceptable".
Fears grew on Friday that Madrid may launch another sovereignty grab over the territory after the wording appeared in a proposed document granting Brits visa-free travel in Europe.
In the proposal put forward by the European Parliament, which is expected to be passed into legislation, UK citizens travelling to the the Schengen area after March 29 should be granted visa-free travel for a short stay, defined as 90 days in any 180 days, even in the event of no-deal Brexit.
But in the ruling the EU called Gibraltar a “colony of the British Crown” prompting a fresh row over the territory.
The text said: “Gibraltar is a colony of the British Crown. There is a controversy between Spain and the UK concerning the sovereignty over Gibraltar, a territory for which a solution has to be reached in light of the relevant resolutions and decisions of the General Assembly of the United Nations.”
The Prime Minister's official spokesman responded: "It is completely unacceptable to describe Gibraltar in this way.
"Gibraltar is a full part of the UK family. This will not change due to our exit from the EU."
Gibraltar's chief minister Fabian Picardo accused Madrid of trying to "bully" the British Overseas Territory by demanding the contentious description in the draft document.
The Gibraltarian government said "the use of such language, were it to materialise in the final documents, does not assist the creation of a climate of understanding and trust between Gibraltar and Spain as we prepare to leave the EU".
Mr Picardo added: "No one will be surprised to hear the Spanish government making provocative statements in respect of Gibraltar.
"The 32,000 people of Gibraltar are used to the constant attempts by successive Spanish governments to bully us in every possible way.
"This is no different to the sort of abuse we have had from former Spanish administrations."
A row with Spanish Prime Minister Pedro Sanchez over Gibraltar almost derailed efforts to agree the Brexit withdrawal agreement between Theresa May and the EU in November.
The diplomatic spat was resolved after a clarification about the legal position and emergency talks involving Mr Sanchez, European Council president Donald Tusk and European Commission president Jean-Claude Juncker.
