Negotiations in the Brexit talks on Northern Ireland stumbled on Thursday as discussions on the Border revealed new important differences between the UK and EU.

The impasse may block progress towards an interim agreement in December. The hope is that phase one discussions, the divorce talks, would reach “sufficient progress”, to allow negotiations to open in December on the future relationship between the EU and UK.

Talks in Brussels this week are about a stocktaking of progress so far, and a new “state of play” paper from the European Commission has upset the British delegation. It insists any frictionless border will only be possible if Downing Street gives commitments to avoid any “regulatory divergence” between the North and the Republic to allow goods to travel freely and unchecked across the Border because they meet the same regulatory standards.

Britain is understood to argue that while it will seek specific solutions to Northern Ireland’s problems, it does not wish to make such commitments at this stage.

Beyond the mandate

The UK is believed to feel that the paper goes beyond the mandate of the commission task force. Commission sources suggested that there was nothing new in warning that regulatory divergence would necessitate border controls.

At the summit in Brussels 10 days ago, Taoiseach Leo Varadkar made it clear that Ireland believes the UK must be more specific in the phase one talks about the practicalities of achieving the frictionless border that all are agreed is desired. He said the commission negotiators share this view.

Last night a spokesman for the Department of Foreign Affairs said: “The optimal solution would be for the UK to remain in the customs union and single market. . . it is essential for the UK, at the very least, to commit to ways that ensure that a hard Border is avoided and protect meaningful North-South co-operation and the all-island economy.

‘Internal market’

“This must include avoiding the risks presented by any regulatory divergence from the rules of the EU internal market and customs union.”

A spokesmen for Britain’s department for leaving the EU said: “The government has been clear that the UK is leaving the single market and the customs union. It has also been absolutely clear that it is committed to avoiding a hard Border.

“We recognise that the solutions to the unique circumstances in Northern Ireland must respect the integrity of the EU single market and customs union.

“But they must also respect the integrity of the United Kingdom.

“The government is determined to find specific solutions to Northern Ireland’s unique circumstances, not least as the only part of the UK to share a land border with an EU member state.”