I HAVE in the past offered a conditional defence of constitutional monarchy.

As long as three basic conditions are met, I have emphasised the benefits of the monarchy, in terms of unity, continuity, tradition, stability, and non-partisanship.

Those conditions are: (a) that the monarchy enjoys broad public approval; (b) that the monarch and royal family behave ­themselves properly, performing their duties without scandal, and setting a good example of public service, and (c) the monarchy is narrowly confined, by a democratic written constitution, to a ceremonial figurehead role.

If these conditions are not met, monarchy becomes unjustifiable. If the monarch ceases be a unifying figure and becomes an object of political division, then we might as well have an elected head of state.

The method of ­electing a president used in Malta – which requires a two-thirds majority vote in parliament – would be more likely than hereditary succession, in that case, to produce a head of state who enjoys broad cross-party support.

Likewise, the institution becomes untenable if members of the royal family misbehave.

Their only course of action then is to abdicate, or ­totally withdraw from public life, in the hope that the monarchy can remain relatively ­unsullied.

Although monarchs are not elected, they are responsible. It is always possible for Parliament to pass an Abdication Act, Regency Act, or Exclusion Act, and have them pushed aside.

The third of these conditions in the UK has never been met because we do not have a ­properly constitutional monarchy.

Indeed, the main problem with the UK is not that it is too monarchical, but that it is insufficiently constitutional. This condition has, however, been generally met in the other Commonwealth Realms, especially those whose constitutions were adopted after the Second World War.

The King of the United Kingdom has all sorts of weird powers and privileges that are quite difficult to define, let alone defend in a democracy. The King of Belize or the Solomon Islands does not.

My view was always that Scotland should keep the monarchy after independence, if ­constitutionally trimmed down to size.

The King of Scots should be allowed to wave from coaches, prance about in uniforms on ­ceremonial occasions, cut ribbons, and shake hands with ambassadors. But he should ­otherwise be kept strictly away from the levers of power, and placed beneath a written constitution based upon popular sovereignty.

Keeping the monarchy, I argued, was a ­necessary concession to conservatives, to ­ensure that the loyalty of the colonels, lairds, and worthy denizens of golf clubs, would be transferred to the new Scottish state.

Indeed, the re-assertion of the monarchy’s Scottishness, recognising its links to a ­pre-Union Scottish Kingdom, seemed an integral part of the national state-building project.

The Scottish Provisional Constituent ­Assembly’s draft ­constitution, drafted in the early 1960s, made much of this: the monarch was to be proclaimed at the Mercat Cross in Edinburgh (Art. 28), crowned in Edinburgh with the Scots crown (Art. 29) and bound by oath to uphold the ­Scottish Constitution (Art. 30).

Thus, the monarchy would, on the one hand, be a symbol of a continuing British identity, for those who need it, while also being a symbol of a Scottish statehood that is recovered, rather than invented, by independence.

In the meantime, acting with “all loyalty to the Crown” made the Scottish national ­movement respectable. It was a symbol of our ­willingness to work within the existing ­British state to achieve our aims in a lawful and ­democracy way.

Now I am not so sure the circle can be squared. The coronation seems weird and silly. There’s even a Coronation spoon, dating from 1150. It is a very English event. A vital part of English culture is a deep love of doing silly things in a serious way, and serious things in a silly way – but that does not hold true in Scotland.

In 1953, monarchical pomp and pageantry looked impressive, because the British state it represented served the people. Now, in ­Britain’s much-reduced circumstances, it all looks faintly ridiculous: all coronets and no Customs Union.

British institutions have become a ­liability. Have you seen the terrible state of the place? How badly we are led, governed, and ­administered? How dysfunctional those institutions have become? Have you seen the extent of authoritarian powers granted by the Public ­Order Act? Although the King is not ­responsible any of this, he is unavoidably tainted by it.

He is tainted, too, by the refusal of the UK Government to allow Scotland to vote on our independence. “Monarchy-by-consent” falls flat when it is associated with a state that will not allow self-determination.

If Charlie wants to be King of Scots, the path is open to him. But if he tries to use the power and influence of the Crown to thwart independence, it will only make a Scottish ­Republic more ­likely.