The British government has spelled out the extent to which North-South cooperation could be affected by Brexit through publication of a sensitive document that formed part of the negotiations.

London has published a list of 156 areas of North-South Cooperation that were explored in the so-called “mapping exercise”, which in the summer of 2017 examined how such cooperation could be undermined by Brexit.

The report has been published on the website of the Department for Exiting the European Union (DExEU).

A six-page technical note which accompanies the list states: “All areas of cooperation reflect policies or practical cooperation that has been supported on a cross-community basis in Northern Ireland.”

The mapping exercise, which involved British and Irish civil servants, as well as teams of officials from the European Commission, emerged as a key argument put forward by the Irish Government and the EU Task Force as to why Northern Ireland should remain aligned with the Republic in terms of single market regulations.

The list covers scores of areas of cooperation.

They are recorded under 14 headings, including the North-South Implementation Bodies which were agreed under the Good Friday Agreement.

The other 13 headings including agriculture, environment, transport, health, tourism, education, energy, higher and further education, telecoms and broadcasting, sport, art and culture, justice and security, inland fisheries and “other areas”.

It is understood DExEU published the list followed several requests from the House of Commons Committee on Exiting the European Union.

The list of areas is accompanied by a technical note explaining the origin, nature and context of North-South cooperation.

The European Commission has said it will publish its own report on the mapping exercise soon.

The UK technical note says: “The objective of the mapping exercise was to chart the range of formal and informal cooperation that currently exists between Northern Ireland and Ireland, noting the role of EU regulatory frameworks, where applicable, in its operation and development, with a view to maintaining North-South cooperation following the UK’s withdrawal from the EU.”

The note says that Article 13 of the Withdrawal Agreement, which seeks to ensure the continuation of North-South cooperation, does not affect the Good Friday Agreement in how it provides for such cooperation, via the so-called Strand II element.

The paper says that North-South cooperation is not always underpinned by EU rules, and on occasion it is only “partially” underpinned by it.

Other areas are “directly underpinned” by EU law.

The report highlights how a “common EU environment” has helped in cross-border security.

The note states that “the cross-border policing strategy, justice cooperation on public protection, support for victims, youth justice and criminal justice [benefits from] a common EU environment and with EU measures underpinning much of the operational police cooperation, including in terms of combating the threats posed by terrorist groups, organised crime gangs, and cross-border illicit activity.

“Close and effective operational cooperation between PSNI and An Garda Síochána has been critical to tackling shared challenges and threats, and the relationship has led to excellent disruptive and criminal justice outcomes in both jurisdictions.”

It also highlights the importance of EU rules on health, in particular the All Island Congenital Heart Disease Network, which allows health services on both sides of the border to cooperate and ensure that “vulnerable children receive treatment on the island of Ireland”.

While the services is underpinned by a North-South legal agreement: “There is also EU law linked to the operation of the All-island Congenital Heart Disease Network. For example, the directive on the recognition of professional qualifications provides the framework for recognising professional qualifications across Member States.”