Northern Ireland Secretary James Brokenshire said Northern Ireland remaining 'in' while the rest of the UK leaves the EU would be 'impossible' Photo: PA

Ireland is demanding Britain signs up to some 100 rules and regulations in order to ensure an open Border with the North.

The toughened Irish stance, reflected in a leaked European Commission document, is said to have blindsided British officials at Brexit negotiations in Brussels yesterday.

The demands have also thrown British hopes of opening trade and transition talks this December into renewed doubt. UK officials had believed the question of how to avoid a hard Border had been 'parked' until the EU opened talks over trade and the future relationship.

However, the leaked talking points paper entitled 'Dialogue on Ireland/Northern Ireland' shows Irish officials now pushing hard for concrete reassurance on the Border question ahead of a crucial EU leaders' summit in December.

The one-page paper stated that in order to preserve the Good Friday Agreement peace deal, the Brexit divorce deal must respect "the integrity of the internal market and the customs union".

It added that it is "essential" that the UK commits to avoiding a hard Border by remaining part of the EU customs union and continues to abide by the "rules of the internal market and customs union".

It concluded that Britain must ensure "no emergence of regulatory divergence" from the rules of the EU single market and the customs union which are "necessary for north-south co-operation, the all-island economy and the protection of the Good Friday Agreement".

The Irish position was described by a senior EU source as reflecting the "state of play" on the Irish question and reflected the "guiding principles" of the EU's approach to the problem.

It is understood that there are about 100 EU rules and regulations, including many covering customs and agriculture, that Ireland wants maintained to ensure an open trade Border.

But British officials are concerned that the demands present an apparently impossible dilemma. They fear it either means the UK remains in the EU customs union and accepts the rules in entirety, or gives the North special status in the EU that would undermine the territorial integrity of the UK.

UK officials have already warned that any attempt to create a special status would have a destabilising effect on the Good Friday Agreement. The gambit also comes just days after James Brokenshire, the UK's Northern Ireland secretary, travelled to Brussels to meet Michel Barnier, the EU chief negotiator, and a host of MEPs and other top officials.

Mr Brokenshire said he found it "difficult to imagine how Northern Ireland could somehow remain 'in' while the rest of the country leaves".

But the Irish paper flatly challenged that position, with an EU source telling 'The Daily Telegraph' that there were signs Dublin could use the ongoing tussle over the €60bn bill as a pretext for holding up 'sufficient progress' in the talks.

A senior Government source said the British should not feel blindsided.

"We have a taskforce on what we want - it's nothing that would surprise. We want to ensure the common travel area, north and south cooperation to continue, and no hard Border, thus regulatory equivalence between north and south on customs," the source said.

Irish Independent