Despite its reaffirming, in another position paper on Tuesday, that it intends to leave Europe's customs union and strike new trade deals with the rest of the world, the United Kingdom government believes it is possible to maintain a "seamless and frictionless" border in Ireland. Hence, management of the border is a highly sensitive issue and one of three main priorities in the Brexit negotiations.
The UK also said that today's paper will make clear its plans to protect the Common Travel Area (CTA) between Ireland and the UK and the rights for citizens that go with it.
The only European Union country with which the United Kingdom has a land border is its former colony of Ireland, but the Theresa May government announced on Wednesday it wants the current borderless arrangement between the two countries to continue after Brexit.
"We want the European Union funding that has helped victims of the Troubles and cross-community groups to continue at least until the current programme finishes", Theresa May said in an article in Northern Ireland's Irish News newspaper.
But Irish Foreign Minister Simon Coveney was more positive.
On Wednesday, the government expressed plans for no hard border between Northern Ireland and the Republic of Ireland after Brexit. "Our dialogue should, at the earliest opportunity, focus in particular on the issues most critical to delivering as frictionless and seamless a border as possible: customs arrangements, and checks and processes on particular goods", the paper said.
'Completely unacceptable " A British government source said: "As Michel Barnier himself has said, the solution can not be based on a precedent so we're looking forward to seeing the EU's position paper on Ireland.
Politicians in Northern Ireland have warned that Brexit is likely to add to sectarian tensions and could entrench a political standoff that has damaged the economy.
Despite predicting the "row of the summer" over the sequencing of negotiations, Brexit Secretary David Davis in June accepted the European Union's proposed timetable.
The U.K. proposal would essentially continue the current customs union beyond March 2019 for a temporary transition period, but allow the U.K.to negotiate bilateral trade deals with individual countries, including non-EU countries, to be implemented only after the end of the transition period.
The imperative for progress in the talks was spelled out this week when the EU's chief negotiator, Michel Barnier, reacted to the Government's publication of a paper on potential future customs arrangements by saying there must be progress in the first phase before there could be talks on trade.