We need data on how many European Union citizens work in the NHS in Northern Ireland

In comparison with England and Wales we have very poor data on how many EU citizens work in the NHS, this at a time of considerable staffing shortages.

There are 35 NHS Trusts in England where more than 1 in 10 of the staff are Europeans.

These hospitals are generally in the wealthy southeast rather than the north. But with our border with the Republic we can’t pretend that Northern Ireland will be like the north of England in terms of staffing dependency.

How many Irish staff work at Altnagelvin or the Sperrins Lakelands hospitals? Historically, even pre-dating EU membership, the Common Travel Area meant there has been no health services need to know the answer.

Regardless of offers of residency to current staff, ending freedom of movement does suggest in the post-Brexit future that the recruitment supply line between the EU will be disrupted, perhaps ended.

With respect to the EU the UK government may extend an existing immigration scheme that eases the recruitment of clinical staff from the rest of the world.

There are no guarantees though as a further decline in the value of the pound and additional form filling around immigration eligibility may prove to be the tipping point for many potential recruits.

Republic resident NHS staff look set to become in EU terms ‘frontier workers’, whose travel will become more difficult unless there is the same sort of flexibility used to allow French workers access to jobs in Switzerland.

The EU has not declared a position yet.

There are plausible reasons why nationality and residency data have not been collected to date. Partly it’s about not wishing to harm community relations.

There are few circumstances where demanding information about people’s identity is welcomed.

The act itself of asking European and Irish citizens to provide details might also have encouraged them to begin looking for jobs in their home countries.

Would the Department of Health have been pressured into ordering a detailed census of nationality and residency status had there been an Assembly in place during the Brexit negotiations? Parliamentary pressure led to this in England and Wales but not in Scotland.

The clock is ticking with a hard Brexit looking likely now.

The issue needs prompt re-examination with previous considerations set against the lack of preparedness that comes with not having adequate data on nationality.

• Dr Gordon Marnoch is reader in Public Policy at Ulster University