As the united kingdom prepares to slip its European moorings, the ties that bind it together are also under strain. In Northern Ireland, which (like Scotland) voted to remain, there is often talk that a “hard Brexit” could even build new momentum for a united Ireland. One reason for doubting this, however, can be summed up in a word: health.

The 1.8m people of Northern Ireland enjoy free access to the British taxpayer-funded National Health Service (nhs). The Republic of Ireland’s 4.8m residents have to make do with something less appealing. “I know people up north whose life’s ambition is to see a united Ireland, and yet they worry when they see the health service we have down here,” says Louise O’Reilly, an mp in Dublin and health spokesperson for the all-island Sinn Fein party.Check