Guardian exclusive. A home grown plan for checks at NI ports, rejected by the DUP but still in play

A backup plan to impose border checks on trade between Northern Ireland and the rest of the UK at ports and airports to avoid a hard border with the Republic of Ireland after Brexit has been drafted by senior civil servants.

Despite the Democratic Unionist party (DUP) angrily rejecting any suggestion of a border “in the Irish Sea”, a leaked paper reveals that officials have been working on a blueprint “to be deployed as necessary in the negotiation process”

While acknowledging these could be seen to be “inherently incompatible positions”, the paper – drawn up by senior officials working on Brexit in the Northern Ireland executive – argues that “ports and airports provide helpful opportunities for surveillance that assist with risk management even when they do not have any of the visible paraphernalia of a border.

The DUP leader, Arlene Foster, has claimed that opting for checks on trade between Northern Ireland and the rest of the UK would be constitutionally unacceptable and economically catastrophic.

The document deals with this claim by stating: “Concern that a model without a land border would imply ‘a border in the Irish Sea’ could be addressed by providing a ‘green channel’ for goods moving between Northern Ireland and Great Britain, so that there need be no check or constraint on movement.”

It adds: “The very simple and important practical point is that loading on to a ship or aeroplane always involves both a pause in movement and some checks of ‘entitlement to board’ – obviously neither if these apply at the land border. Pragmatic extension of a present reality, with the lightest possible touch required to manage risk, seems infinitely preferable to ‘a return to the border of the past’.

The leaked document suggests there would need to be a requirement on traders between Northern Ireland and Britain to provide information ahead of time for it to work, and “a system of random and intelligence/data-based checks” on goods going through the “green channel”.

Goods moving from Ireland to Britain via Northern Ireland would be subject to checks in a “red channel” at the port or airport where they leave the island of Ireland.

Imports from Britain and the rest of the world to Northern Ireland that are not permitted to enter the single market would also be subjected to “red channel checks”, with “draconian penalties for non-compliance”.

“The degree to which these protections are needed would depend on the degree of regulatory divergence that would apply sector by sector, and clearly that may evolve over time from the status quo of regulatory uniformity,” the 19-page document says.

Officials concede in the document that a major test of their approach would be whether it was “perceived politically as in effect creating a hard border with the UK (or between Ireland and the rest of the EU)”.

It is also recognised that keeping the border on the island of Ireland open will allow goods not compliant with EU or UK trade policy to move freely around the two jurisdictions. “But the same risk is tolerated to some degree in other contexts (eg between Switzerland and its EU neighbours),” the paper argues. “The commitment to support the all-island economy suggests that some degree of risk can be accepted.”

The paper is believed to have been drafted by Andrew McCormick, Northern Ireland’s director general of international relations for Brexit, with oversight from the head of the Northern Ireland civil service, David Sterling. It was shared with the DUP earlier this year, and the party reiterated its opposition.

The Sinn Féin MEP Martina Anderson said: “This proposal offered a workable solution which would see the north remaining in the customs union and mechanisms put in place to protect trading arrangements between Ireland, north and south, and Britain.”

Brexit negotiators side-stepped any discussions about the Irish border in Brussels this week, instead publishing on Friday an agreed list of subjects to be discussed in the coming trade talks, ranging from financial services to fisheries.

The Brexit secretary, David Davis, said: “Both the United Kingdom and European Union remain committed to reaching agreement on the terms of our future partnership by October, in addition to finalising the withdrawal agreement including the protocol on Northern Ireland.”

Former BBC journalist and manager in Belfast, Manchester and London, Editor Spolight; Political Editor BBC NI; Current Affairs Commissioning editor BBC Radio 4; Editor Political and Parliamentary Programmes, BBC Westminster; former London Editor Belfast Telegraph. Hon Senior Research Fellow, The Constitution Unit, Univ Coll. London