It states that “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”.
This means the Spanish Government, led by Prime Minister Pedro Sanchez, has a key veto on all potential agreements between Madrid and London.
But Mr Buttigieg believes this essential veto over Brexit talks is “undemocratic”, and says Brussels should instead focus on the behaviour of Spain.
He said: “It is undemocratic, we should not be speaking of vetoes in this day an age. To bestow upon Spain the power to hold the UK to ransom, it is unjustified and unfair.
“It is understandable for the EU to defend their member state, they are scared of Brexit being a success. I think the EU stance is understandable, but not the best stance.