No agreement has yet been reached on the right operational approach to avoid a hard Irish border, the EU’s draft agreement showed.

A “backstop” solution envisaging Northern Ireland effectively remaining within the EU customs union if no other solution is found has been assented to in principle.

All sides are united in their desire to create a frictionless border after Brexit and the issue is expected to dominate talks next week.

The document said: “The negotiators have reached agreement on some elements of the draft protocol.

“They further agree that the full set of issues related to avoiding a hard border covered in the draft reflect those that need to be addressed in any solution.

“There is as yet no agreement on the right operational approach, but the negotiators agree to engage urgently in the process of examination of all relevant matters announced on 14 March and now under way.”

Theresa May’s DUP allies are adamantly opposed to any deal creating a difference between Northern Ireland and the rest of the UK.

Details not yet agreed between the EU and UK included:

– Measures creating an area without internal borders in which the free movement of goods is ensured and North-South cooperation between Northern Ireland and the Republic is protected.

– Prohibiting customs duties on imports and exports between the EU and UK specific to Northern Ireland, including duties of a fiscal nature.

– The banning of restrictions on imports and exports between the EU and Northern Ireland.

– Internal taxation rules.

– The application of EU law surrounding VAT and excise duties, agriculture, fisheries products and environmental protection to Northern Ireland.

Laws were agreed in principle surrounding state aid and the wholesale electricity markets; Northern Ireland is part of an island-wide energy market.

The Common Travel Area allowing free movement of UK and Irish nationals between Ireland and the UK was agreed.

The draft agreement said: “With respect to the draft protocol on Ireland/Northern Ireland, the negotiators agree that a legally operative version of the ‘backstop’ solution for the border between Northern Ireland and Ireland…should be agreed as part of the legal text of the Withdrawal Agreement, to apply unless and until another solution is found.”

The EU and UK agreed to maintain the necessary conditions for continued North-South cooperation, including in the areas of environment, health, agriculture, transport, education and tourism, as well as energy, telecommunications, broadcasting, inland fisheries, justice and security, higher education and sport.

Brexit Secretary David Davis said it remained the UK’s intention to achieve a partnership that was so close it did not need Northern Ireland-specific measures and pledged to engage in detail on all scenarios set out in December’s Joint Report between the two sides.

He said: “We have also reached consensus on the full set of issues which need to be addressed in any solution in order to avoid a hard border, which is why, last week, we set out a work programme to tackle them.

“There are also some elements of the draft protocol, such as the Common Travel Area, on which we agree.

“So while there is as yet no agreement on the right operational approach, we know what we need to do, and we’re going to get on with it.”

A spokesman for Taoiseach Leo Varadkar said Britain’s commitment to a “backstop” solution to avoid a hard post-Brexit border is legally firm and will apply until something better is agreed.

He told RTE: “The backstop is as legally firm as the government said it would be in December.

“The UK has today publicly accepted the need for such a backstop to be in the text of the (EU) withdrawal agreement.”