Asked in his old age to explain the causes of the Spanish Civil War, General Franco’s brother-in-law and former Foreign Minister Ramon Serrano Suner replied : “ We simply couldn’t stand each other”.

The new divide transcends and destroys the old party political voting patterns

Although not (yet) at physical war, Britain’s two new warring tribes have reached a level of mutual loathing and open contempt similar to the unreasoning hatreds that tore Spain apart in bloody fratricidal strife between 1936-1939.

As the Dominic Cummings affair has just demonstrated anew, the yawning gulf between the two tribes first exposed by Brexit has widened to such an unbridgeable chasm that it is difficult to see when or how it can be healed.

Once you know how someone voted in the 2016 referendum, it becomes easy to guess their opinions on a whole range of issues. Leaving aside the first two Tory MPs to call for Cummings’ head, Steve Baker and Peter Bone, (who both still had personal ‘issues’ with Cummings dating from the Brexit campaign); it is no coincidence that the overwhelming majority of Cummings’ Conservative critics were Remainers in that battle, and have neither forgotten nor forgiven their defeat at his hands.

Outside the ranks of the Tory Parliamentary party, the same rule applies. Scratch a Twitter warrior bellyaching about Boris or moaning about the Government’s admittedly inept performance in the Coronavirus crisis, and you will find the wounds of 2016 still glistening red and raw.

It is no accident that the two newspapers who cooperated to expose Cummings’ journey to Durham, the Mirror and the Guardian, were the most vociferous Remain cheerleaders of the Press pack during the Referendum and have been patiently waiting to take their vengeance on Brexit’s principle architect ever since. For, as the Italian proverb has it, revenge is a dish best eaten cold.

But the Brexit divide goes far wider and deeper than the conduct and character of either Boris Johnson or Dominic Cummings. Roughly speaking, if you are an academic, a civil servant, a BBC journalist,  a Metropolitan London resident or a reader of the aforesaid newspapers you are likely to be a member of the Remainer tribe. If you work manually, live in the north or a coastal town (Brighton apart), are a thrusting entrepreneur, or still feel pride rather than shame in Britain and it’s history then you will probably find yourself in the Leave camp.

The new divide transcends and destroys the old party political voting patterns. Former Labour voters in Stoke, Sunderland and Sheffield helped demolish the Red Wall at the General Election in December and handed Boris his 80-seat majority largely because of their party’s weaselly ambiguous stance over Europe, while the once true blue Tory seats of Putney, Canterbury and Cambridge are Labour now primarily because of Brexit.

What is also new is the simmering cauldron of poisonous hatred that Brexit has bred. Soon after the 2016 referendum I wrote a piece for the Telegraph recalling the English Civil War of the 1640s, and warning that divided nations often end by settling their differences violently. We have not yet arrived at that journeys end, but four years on we are a good deal farther along that dangerous road.

Predictions that actually achieving our exit from the EU would begin to heal our divisions and that the losing side would accept their defeat gracefully have proved far wide of the mark. Instead, those divisions have hardened into fixed trench lines from which the two sides snarl at each other across no man’s land behind impenetrable barbed barriers of mutual misunderstanding, fear and loathing.

Thus far hostilities have been kept to a kulturkampf: confined to a war of words conducted in op ed newspaper columns, broadcasting studios and above all on social media. But the abuse, insults and bile spewed out there are something  new and ugly in British political discourse and generate heat rather than light.

In the hot summer of 1936 the long-stoked class hatreds and social injustices that had disfigured Spain and split landlord from peasant, army from politician, and Left from Right exploded into open and ruinous violence that killed half a million – many of the victims innocent civilians slaughtered behind the lines by their ideological foes on both sides just because of their political beliefs.

I do not suggest that we are remotely near there – this is Britain after all – but the bitter hatred and contempt that has split families and generations, sundered friendships, and destroyed our cosy standards of polite political dialogue is there all right and shows every sign of being permanent. If that doesn’t worry you, it should.