It is hard now to see an easy way forward for Catalonia

Catalonia is the wealthiest region of Spain and popular with British tourists, including numerous coastal resorts and the great city of Barcelona.

But nationalist tensions have been simmering there for years, and have erupted over the weekend.

In many respects the response of Madrid towards the constitutional integrity of Spain is admirable. The status of a region and its right to secede is not just seen as a matter for the region, but for the whole nation. The United States has the same approach to its own states.

Imagine the United Kingdom took the same approach to Northern Ireland or Scotland – they cannot leave the Union without consent of the rest of the UK. It would be a logical stance but would inflame a sense of nationalist grievance. Inflamed local feeling is just what has happened in Catalonia.

Madrid’s response to stop the referendum was tough and looked ugly. This could prove disastrous for Spain, if the backlash in Catalonia is fierce.

Britons who live in Gibraltar are familiar with Spanish hardball tactics, which they fear will get worse post Brexit. But in this showdown the Catalan regional government has also behaved badly, and set the scene for a confrontation.

It will be a tragedy if a great global nation such as Spain splinters into smaller bits , in much the same way that a splintered UK would be a much diminished one.

It is hard now to see an easy way forward for Catalonia. At some point feeling in the region will either have to be seen to have been put to a fair electoral test, or resentment will almost certainly grow. And even a future poll scenario assumes that the current fury can be contained, which it might not be.

But at the same time it is refreshing to see Spain defend itself as a nation. London always seems afraid of separatists, and since the 1990s has been at pains to state it is neutral over Northern Ireland.