“There’s been a lot of positive working together previously but I’d say, over the last seven days or so, that has definitely come under strain.
“There were frustrations there before, but if things carry on as they are there’s real potential for trust to be damaged.
“I don’t think we’ve seen anything deliberately antagonistic between the four national leaders, so while I think and hope those relationships are surviving, I think we may see some difficulties and frustrations between officials in the future.”
Greenough said media briefings in early May targeting Westminster journalists and resulting in front pages announcing “freedom” from lockdown days before any formal announcement was made (and before devolved leaders or any MPs were told) were damaging.
“That sort of briefing happened during Brexit negotiations and it was sort of fair game then,” the former speechwriter said.
“Yes, it was calculated and annoying, but in ‘peace time’ it was almost expected. But these are not normal times, and now it’s not annoying – it’s dangerous.
“It’s not how to run things, and it’s not how to keep the devolved administrations as equal partners.”
Welsh politicians have argued that a united front is vital for keeping people – particularly those who live close to national borders – safe in the coming weeks, with health minister Vaughan Gething confirming “stay at home” advice would remain in place until at least Thursday.
“Places like north-east Wales and north-west England are basically one region,” Greenough said. “People do not see the border in their everyday lives – it doesn’t really exist for them.
“Wales took a cautious approach regarding easing lockdown last weekend because all four police forces reported an increase in the number of people entering Wales from outside.
“We are dealing with something extremely sensitive and important here, and it’s an absolute case in point as to why we need to see a mutual respect between the Westminster and devolved administrations.”
Rob Roberts, the first Tory MP elected in the north-east Wales border constituency of Delyn for more than 25 years, said the different messaging between nations had led to confusion among the public.
“I represent people who live in Wales but work in England, and there are lots of people who travel from England to work in Delyn. They’ve been in touch because they don’t know what they can and can’t do, and all sides seem to be blaming each other for the confusion,” he told HuffPost UK.
“There’s a mechanism in the agreement with the devolved administrations that allows the national government to take control in an emergency, and to be honest if it hasn’t been used under these circumstances, I don’t know when it ever will be.
“I don’t know if it was considered, and if it was I am sure the PM decided against that cause of action because of his respect for devolution, and of course I support that.”
Roberts said he was “positively not suggesting” the scaling back of devolution in general.
He added: “But if we had taken that approach, we would have avoided all of the mixed messaging, tit-for-tat and one-upmanship that I think we’ve seen, and which really annoys people.
Scottish secretary Alister Jack told MPs the R rate – which represents the reproduction rate in the virus – was at a different rate in different parts of the country, including in Scotland.
Sturgeon effectively put Scotland in lockdown earlier than other parts of the UK by closing schools, but she has recently come under fire for the rate of deaths in Scottish care homes, though she denies it has risen to double that of England.
Scotland’s FM has an approach that has differed only slightly from Johnson’s, with schools set to return to August as opposed to June, and restrictions on socialising loosened to a greater extent.
As it stands, polls suggest the 2021 Holyrood elections will see the SNP once again hold the balance of power north of the border, at which point Sturgeon may again press for a fresh referendum.
Divisions could start to arise before then, however, as power-holders will urgently need to turn their attention to rebuilding the economy.
Chancellor Rishi Sunak is predicting a recession “like we have never seen” before and the spectre of mass unemployment sits on the horizon.
How leaders negotiate this will be key.
The SNP is already pushing hard for a universal basic income and further controls over immigration policy, while Labour’s Keir Starmer advocates a “new settlement” and further devolution.
Gray said the four-nations approach could splinter in the coming months, however.
“It is becoming more difficult, partly because the UK government is looking more towards the economic health of the nation,” he added. “I’m certainly very sure we must pick up the pieces of the economy thereafter, but I think the focus has got to be, from a government perspective, on making sure that the health crisis is dealt with first.”
Leaders from the English regions, such as Manchester’s Andy Burnham, will also be trying to wrest more control from Whitehall, though most recognise the eye-catching press calls are for a later date.
In Northern Ireland, where DUP leader and first minister Arlene Foster has said “different parts of the UK move in different time” to respond to the outbreak, there is no mood to open up division and constitutional politics, even among some nationalists.
MP for Foyle and SDLP leader, Colum Eastwood, whose party advocates a border poll, said relations between the nation and the rest of the UK remain intact.
Brexit and the question of the Irish border may prove a bigger fault-line between Johnson and Ulster, with the UK set to leave the transition period with the EU in December and Johnson seemingly having broken his promise of no checks between NI and Great Britain.
Eastwood told HuffPost UK: “The scale of the crisis we’re facing, not just across these islands, but across our continent and across the world, has driven a sense of social solidarity.
“People are making enormous sacrifices and staying away from friends and family to keep each other safe. There was a huge volume of good will toward governments to get the response right.”
With the region sharing a land border with the Republic, Eastwood said there is a certain level of detachment from Westminster.
He said: “The virus hasn’t damaged relationships across these islands but the Conservative administration’s response has certainly made people look elsewhere for leadership.
“In Northern Ireland, for example, people have been accepting the advice of the Taoiseach, our executive and even the Scottish First Minister before they’ve accepted Boris Johnson’s approach.
“They’ve never been so glad to have devolution and autonomy to break from London. That may have an impact on their attitude to the British government. But our first priority is to keeping people safe. The constitutional outworking will wait for another day.”
Labour’s newly-appointed shadow Scotland secretary Ian Murray was also keen to stress unity.
Saying “there are far more important things than arguing about the constitution”, he acknowledges that “we can’t go back to the same old politics”, as the fallout from the lockdown will throw up questions about the economy.
He said: “This crisis is teaching us again the value of community, of solidarity and pulling together towards a common goal regardless of geography. The politics that emerges from this crisis has to reflect that.
“The only priority for all governments, long after lockdown measures are lifted, will be to protect and restore people’s jobs and livelihoods by working together for that common goal.
“Constitutional politics has to be set aside by both the UK and Scottish governments and replaced with a shared national mission of rebuilding our country.”