Constitutional marriages can be delicate things, having to resist constant pressures from within and without.

Which perhaps makes it all the more remarkable that the one between Scotland and England has lasted for more than three centuries. But are the divorce lawyers now preparing their briefs?

Last week, Mark Drakeford warned the Union had never been so fragile and change was needed urgently or the “case for the break-up of the UK will only increase”. Music, no doubt, to Nicola Sturgeon’s ears.

The Wales First Minister produced a 20-point plan to improve devolution and see the constitutional marriage survive into the future.

But the Labour politician had a warning for Boris Johnson, the self-styled Minister for the Union. He said: “Too often, we see the UK Government act in an aggressively unilateral way, claiming to act on behalf of the whole UK but without regard for the status of the nations and the democratic mandates of their government.

“We see muscular Unionism, instead of working towards a genuinely constructive and collaborative relationship between the governments of the UK.”

This month, the UK Government is set to update on how it’s trying to improve relations between London and Edinburgh.

The so-called Inter-Governmental Review[IGR] started in 2018 and, remarkably perhaps - or possibly not - is still going on.

There was a “progress update” in March, which explained where agreement on some areas had been made and where not.

The Prime Minister has agreed to hold a formal annual summit with the First Ministers of Scotland, Wales and Northern Ireland. It is shocking it has taken 22 years for this to happen; illustrating Mr Drakeford’s point.

There is a new Cabinet Committee on the Union, a Union Directorate and a policy of “Union-think” adopted among civil servants to “ensure UK-wide issues are properly considered and sit at the heart of policy-making”.

In May, Sue Gray returned to the Cabinet Office as Second Permanent Secretary with responsibility for the Union and the constitution; she previously had the grand-sounding title of Director-General for Propriety and Ethics.

The IGR update referred to inter-ministerial groups, an inter-ministerial standing committee, a secretariat to provide administrative support, a dispute mechanism, and increased transparency through “enhanced reporting to their respective legislatures”.

The progress report repeatedly used the words “constructive,” “collaboration” and “consensus” but confirmed there was still no agreement on setting up a key UK Government and Devolved Administrations Council.

Last week, albeit for just 89 minutes, the issue of Union relations surfaced in a House of Lords debate when, discussing the lesser-spotted Dunlop Report on strengthening the UK, several peers let off steam about its fragile state.

Of course, the SNP is not represented in the Upper House, so most of the contributions came from a strong Unionist perspective but illustrated the deep anxiety some have about the future of Britain’s constitutional marriage.

There was a denunciation of reliance on flying the Union flag, most notably one eight-storeys high in a Government building in Cardiff, and the “ridiculous attempt” to get schoolchildren to sing a song for One Britain One Nation Day.  

The Scottish non-affiliated hereditary peer, the Earl of Kinnoull, warned of “significant creaks and groans within the Union” as inter-governmental relations had failed to keep pace with changing devolution.

Lord McConnell, the former Labour FM, noted how anyone born after the creation of the Holyrood Parliament in 1999 would “in Scotland today question the purpose of the United Kingdom - not just the UK Government or Parliament - in their lives”.

But the strongest remarks came from Crossbencher Lord Kerr, who claimed devolution was on “life support”.

The ex-diplomat had a piece of advice for Boris: “Do not go on feeding the perception that you are not really a UK Government but an English Government. Cut out the unforced errors, stop digging the hole deeper and please scrap the hard hat, high-vis jacket photo-op visits, which only annoy. Instead, show parity of esteem, get around the table with your counterparts, settle the structures and make them work. You have not long; time is running out.”

Tory peer Lord Hannan denounced the “trashing of the British brand” but insisted that Britain had a tremendous story to tell as a united people; defeating fascism, ending slavery, spreading commerce and law across the globe. “It is a great song to sing,” he declared, “and we have not finished singing it yet.”

Lord True, Mr Gove’s ministerial chum in the Cabinet Office, sought to paint a positive picture of how the UK Government was working hard to keep sweet its relations with Edinburgh and at times did a fine impersonation of Yes Minister’s Sir Humphrey Appleby.

“The UK Government wish to reconcile competing views, explore external perspectives and ensure all points have been fully considered before concluding.”

The minister denounced the “disparaging comments” made about the PM, stressing how Boris was “deeply committed to strengthening the Union,” and disagreed with Lord Kerr that his visiting all corners of the UK was somehow counterproductive.

“Our aim,” said Lord True earnestly, “is to create a more regular rhythm of engagement and embed a culture of collaboration across all levels of government.”

Once the struggle against the pandemic begins to ease, hopefully soon, the political focus will shift to other matters, including the future of the constitutional marriage between Scotland and England.

Mr Johnson and his Union-fixer Mr Gove have made clear London has absolutely no intention of facilitating Indyref2 while Ms Sturgeon has made it equally clear Edinburgh will stage its own poll on Scotland’s future.

Government lawyers on both sides are dusting down legal tomes to prepare for the mother of constitutional battles in the courts.

The die-hards on both sides of the Union/independence divide might relish the political ding-dong but, for many Scots, hearts will sink and eyes will roll.

They will again feel stuck in the middle of this never-ending psychodrama, which they have endured for many years and look condemned to do so for many years to come.