IT’S war, by jingo. UK tabloids, exercising their customary dignified restraint, have been rattling sabres at the Spanish  over Gibraltar. The Sun warned that that the British navy could “cripple” Spain. The Daily Mail said we had the “biggest Armada”. So come on “donkey rogerers” , as a Sun columnist called the Spanish people, if you think you’re hard enough … All we need is Jeremy Clarkson to take his car show there.

We knew that Brexit was likely to bring out the worst in the British temperament, but no one expected that we’d descend into post-imperial belligerence less than a week after Article 50 was declared. The former Tory leader, Michael Howard, ignited the row by comparing the current situation to the Falkland’s war in 1982, when a British task force sailed halfway round the world to fight the Argentine army for control of what they call the Malvinas Islands. Theresa May made clear that war over Gibraltar is unthinkable, but the row has reverberated across Europe and damaged Britain’s already-tarnished diplomatic image.

The Battle of Gibraltar was provoked by the EU Council of Ministers saying in its draft guidelines for the Brexit talks that Spain should have a veto over the status for the tiny territory with its 30,000 inhabitants, which is attached to mainland Spain. This apparently came as a complete surprise to Theresa May, though the Gibraltar government had been on at her for months to include Gibraltar’s autonomy in her Article 50 letter in anticipation of something like this.

The enclave was ceded to Britain in the Treaty of Utrecht in 1713, but Spain regards it as an imperial anachronism. However the row is not really about sovereignty. Spain is not actually asking for Gibraltar to became a part of Spain, only that it should have a say in its future, rather as the UK did over the former British colony of Hong Kong. The Rock has very low taxation and has attracted large numbers of banks and offshore companies which have an impact on the economy of the mainland. If Dover were a Spanish tax haven you can imagine the UK Government would want a say in its future.

However, the underlying issue here is a constitutional one. The people of Gibraltar are British citizens, but it is a self-governing territory and only relies on the UK for defence and foreign policy. It is the ultimate form of what used to be called “devo max” in that it controls all its taxation and economic policy, including a 10 per cent corporation tax rate and no VAT. The Rock is proud of its independence and has no desire to become part of Spain, but it depends on a “friction-free” border with the EU and imports many Spanish workers. Free movement is therefore essential for the economic wellbeing of Gibraltar.

The Gibraltarians voted overwhelmingly to remain in the European Union in the June referendum, and like Scotland they want to remain in the single market after the UK leaves. Gibraltar is in the single market without being in the EU customs union or the Common Agricultural Policy. This is not a million miles from the “bespoke arrangement” that the Scottish Government was asking for in the White Paper, Scotland’s Place in Europe, published in December. Indeed, Scotland cited Gibraltar as an example of part of the UK that will remain in the single market after Brexit.

By shining the Article 50 spotlight on Gibraltar and Northern Ireland, Brussels is letting the world know that there are many ways of remaining part of the single market while leaving the EU. There are 13 other oversea territories and also Crown Dependencies like the Isle of Man and the Channel Islands. The Brexiters thought that no one would bother about all these tiny fragments of Britain that have anomalous relations with the EU. Well, now they know.