There are few issues in British politics as potent as the National Health Service. That’s why Labour start trying to persuade voters the Conservatives are going to sell it when they’re completely out of other ideas, and why Vote Leave chose a health spending pledge for the side of their famous bus.

But it might also be one of the main things, below the level of raw constitutional power politics, holding the United Kingdom together. This is what polling by Hanbury found for State of the Union, the latest report on the subject from Onward:

“The only benefit or feature of the United Kingdom that a majority of voters in Scotland, Wales and Northern Ireland would miss in the event of reunification is funding for public services like the NHS. This further underscores the salience of the NHS and the association with subsidy through the Barnett Formula to devolved nations.” 

This finding is bleak on two different levels. First, and most obviously, it should deeply concern anyone who wants the UK to endure that the social bonds of British nationhood have atrophied to the extent suggested by these findings. The ’emotional case’ for the Union has to rest on building up appreciation for British institutions.

Second, there is something starkly mercenary about it. It isn’t “the NHS” voters will miss, it’s just “funding for public services like the NHS”.

Voters can’t be blamed for this. It is a feature of the current ‘devolve and forget’ constitutional settlement that whole areas of policy, including health, are simply devolved wholesale. The Tories might campaign against Welsh Labour’s awful mismanagement of the NHS west of Offa’s Dyke – which David Cameron branded ‘the line between life and death’ – but there is no question of the Government stepping in to help.

The upshot of this is that being part of the United Kingdom increasingly doesn’t and can’t deliver tangible benefits for those public services which matter most to voters – and such aid as is rendered must pass through the hands of the devocrats in Edinburgh and Cardiff, who then take the credit.

The Government has already demonstrated, by passing the UK Internal Market Act, that it is prepared to challenge devolutionary nostrums. Some ministers are already debating ‘UKIM 2’, an as-yet hypothetical bill which could expand the Government’s capacity to act to other areas beyond the maintenance of the British common market.

Onward’s findings should therefore be a call to arms. The national contribution to the ‘National’ Health Service needs to amount to more than cash. The Department of Health should work with the Union Directorate to look at how the British state could directly support NHS delivery in the devolved territories, whether through setting national minimum service safeguards, making it easier for patients to access cross-border treatment, or more besides.

This will inevitably anger the devolutionary purists. Some might even claim, as they have to me, that having ultimate Westminster oversight over the delivery of essential services means its ‘not actually devolution’. But that’s all to the good. They have misruled the unionist movement long enough.