14:22

The deputy leader of the Democratic Unionist Party has knocked back the EU’s suggestion that Northern Ireland remain in the customs union and the single market in order to achieve an invisible border with Ireland.

Nigel Dodds has told the BBC’s John Campbell in Belfast that the EU’s comment “display an unwillingness .. to engage in a meaningful fashion in relation to the border”.

lisa o'carroll (@lisaocarroll) The DUP has expressed its concern over EU document which suggests invisible border only achievable if N Ire stays in customs union https://t.co/BjLj2UqjGo

His remarks come as Brexit secretary David Davis said “frank” discussions had been held with the EU on the border question in this weeks talks.

Davis’s remarks may be seen as an attempt to win recognition that the Northern Ireland border issue cannot be solved in the first of talks because it is linked to the final trading deal with the EU.

He said progress had been made on the common travel area but inferred that there was no sign of a solution on the border question.

“We’ve also had frank discussions about some of the big challenges around the border,” he said. “We remain firmly committed to avoid any physical infrastructure,” he added, reiterating previous promises that there would not be customs inspectors on the ground or watchtowers to police the border.

In August, the UK suggested it could achieve an invisible border with pre-clearance checks on either side and exemptions for small businesses.

However in the September talks the EU dismissed this solution and said it would not allow Northern Ireland to be used as a proxy for talks on the wider question of the future trading relationship between the EU and the bloc.

This week’s leaked document suggests that the EU is doing just that.

The leaked EU document on Ireland says it “seems essential for the UK to commit to ensuring that a hard border on the island of Ireland is avoided, including by ensuring no emergence of regulatory divergence from these rules of the internal market and the customs union.”