Gibraltar have had two referendums on whether they want to be a part of Spain or the UK, and they have voted with an absolutely insane majority to choose to be part of the UK in both cases. This isn't like Brexit, or Scotland's IndyRef - there was a 96% turnout and a 99% vote in favour of the UK in 1967, and an 88% turnout with a 99% vote in favour again in 2002.