Which rather suggests the Gibraltarians don't accept our rule over them do they?Isn't it rather the illustration of a long running conflict between Spain and the UK? A conflict which was calmed down when the UK joined the EU.
In 2000, a political declaration of unity was signed by the members of the Gibraltar Parliament; it stated "In essence the declaration stated that the people of Gibraltar will never compromise, give up or trade their sovereignty or their right to self-determination; that Gibraltar wants good, neighbourly, European relations with Spain; and that Gibraltar belongs to the people of Gibraltar and is neither Spain's to claim or Britain's to give away."
My bold text.
On that basis we should stand back and say to the pair of them
"Sort it out between yourselves and get back to us."