The Brexit negotiations were getting boring – we needed a battle over Gibraltar to spice things up

We may have lost India and the other big stuff, but by God the sun will never set on our Barbary apes or our South Atlantic sheep

Fabian Picardo said not protecting Gibraltar would be like 'giving Cornwall to the French' (Getty)

Just when the process of unravelling Britain from Europe was beginning to look like an anticlimactic doddle, give thanks to a weeny stretch of land by the Mediterranean for injecting a badly needed shot of chaos.

Taken out of context, Gibraltar does not appear to be one of the major items on the roster of assets to be separated. It’s the print of Guernica he bought on a weekend break to Barcelona, perhaps, or that antique copper kettle she picked up for a tenner at the car boot.

Roughly the size of a London park and with a similar population to Exmouth, Gibraltar’s economic relevance seems as negligible as its status as a UK enclave in Spain seems comically anachronistic.

Symbolically, of course, it is more important than the bare statistics imply. To Spain, whose foreign minister was banging on about planting the Spanish flag on the rock within a few days of the Brexit result, the Union Jack’s presence is an insult to machismo pride.

To Britain, still racked by phantom limb pain in the post-imperial stump, retaining Gibraltar (like the Falklands) is a placebo to take the edge off the agony. We may have lost India and the other big stuff, but by God the sun will never set on our Barbary apes or our South Atlantic sheep.

Gibraltar was always certain to be problematic if we voted for Brexit. And now, with Donald Tusk alluding to a Spanish veto over trade talk decisions affecting Gibraltar in his reply to Theresa May’s letter (in which Gibraltar went unmentioned), the sabre-rattling is underway.

Caught in the middle are the 30,000 Gibraltarians whose loyalties are equally ferocious. In recent polling, 99 per cent wished to remain British, and almost 98 per cent to remain in the EU.

In less poisonous divorce proceedings, squaring that circle would be easy. Joint custody of dear little Gib would be awarded via shared sovereignty. The eastern Caribbean island of St Martin/Sant Maarten is shared by France and the Netherlands without any tension or need for a hard border.

With Gibraltar, such a sensible, civilised agreement looks impossible. Not only would it elevate our thuggish right-wing press to a pinnacle of jingoistic apoplexy unscaled since Thatcher decided blood was worth spilling in the South Atlantic. The chief minister of Gibraltar, Fabian Picardo, has reiterated his adamant rejection of Madrid’s joint sovereignty proposal.

He describes the Spanish claim to his territory as “medieval”, which give or take a century may technically be correct: you have to go back as far as 1704, when England and the Netherlands snatched it, for the last time Gibraltar was Spanish. Proving himself almost as naturally gifted a diplomat as Boris Johnson, who rails against this “land grab”, Picardo also calls it “rancid”.

In this febrile atmosphere, Theresa May might feel compelled to ingratiate herself with her bosses at The Sun and Daily Mail with a tonal tribute to the 1982 Thatcher, albeit not necessarily by dispatching a task force to the Med.

Spain, meanwhile, will leave its ability to destroy Gibraltar’s duty free economy floating menacingly over negotiations. All it needs do, as it tends to whenever relations with London are strained over fishing rights, is vindictively make its border checks intolerably long for the thousands who cross it every day.

May would have every right to be livid about that. It is not the British way to use blackmail as a bargaining tool, as her hint about withdrawing security cooperation confirmed. She might also point out that the Treaty of Utrecht, which granted us ownership of Gibraltar, cannot be unagreed. When Britain signs a treaty, it stays signed. Unless it happens to be signed in Rome, Maastricht or Lisbon.

And Spain has every right to regard a foreign power’s ownership of territory within its borders as a gross insult to its sovereignty. The fact that from Gibraltar, on a clear day, you can see Ceuta, one of the two Spanish enclaves in Morocco, has nothing to do with that.

At least the two sides are well matched in hypocrisy, though that may offer small comfort to Gibraltar as it faces an uncertain future as tug-of-love child in history’s most protracted and vicious divorce. In fact, it barely qualifies as a child. This is more a custody battle over which of the parties keeps the shed at the end of the garden that gets all the sun.

If the Nobel peace committee happens to be reading this, the Norman Plan involves Gibraltar yelling “a plague on both your houses” at Madrid and London, and applying to become a constituent part of Scotland. It would then wait patiently for Moses-Joshua Sturgeon to lead her country out of English bondage and back to the euroland of milk and honey.

It isn’t perfect, but it may have to do. In the meantime, the consolation for the 30,000 souls whose sense of security is being sacrificed on the (Gibr)altar of infantile Anglo-Spanish intransigence is that their duty free paradise is the cheapest place on the continent in which to drink yourself into oblivion.