Northern Ireland's High Court has rejected an attempt to block Britain's exit from the European Union, saying neither the province's parliament nor laws could override a decision by the British government.  But it said it would defer to English courts on the wider issue of whether the British government has the right to invoke Article 50 of the EU Lisbon Treaty to leave the bloc, without the explicit backing of the British parliament.  Prime Minister Theresa May welcomed Friday's ruling, with a spokesman saying it would allow the British government "to proceed to trigger Article 50 as planned".  One of the plaintiffs, human rights activists Raymond McCord, said he would appeal against the ruling in the Supreme Court, Britain's highest judicial body.  The case is the first judgment in legal disputes around Brexit that are being closely watched by politicians and markets.  A case in London will rule on whether May can use the government's "royal prerogative" power to trigger Article 50 without consulting parliament.  "The fact that the government has won in the Northern Ireland case could be seen to indicate that its prerogative power is holding up pretty well," said Stephen Tierney, director of the Edinburgh Centre for Constitutional Law.  "I would personally be surprised if the High Court in England reached a different conclusion," he said.  Sterling hit an eight-day low against the euro after the ruling.  Overall, 52 per cent of the UK voted in favour of leaving the EU in June's referendum, but 56 per cent of those voting in Northern Ireland backed remaining in the bloc.  There are fears that Brexit could undermine a 1998 peace deal, the Good Friday Agreement, which ended three decades of bloodshed in the province, and could lead to the reintroduction of unpopular controls on the border with the Republic of Ireland, an EU member.  But justice Paul Maguire said it was "not viable" that Northern Ireland should overrule the 52 per cent of the UK as a whole that voted in favour of leaving.  The regional parliament would have a say on legislation passed to enact Britain's exit, but the triggering of Article 50 itself was not a "devolved matter".  "The UK Parliament has retained to itself the ability to legislate for NI without the need to resort to any special procedure," Maguire said.  The arguments about May's rights to trigger Article 50 "have been held over pending the outcome of the English litigation", he said.  Rights activist Raymond McCord told journalists at the court that the ruling was just a setback and he would continue to fight Brexit.  "I believe what we are doing is correct. Fifty-six per cent of the people of this country (Northern Ireland) voted to remain."  A group of politicians and rights groups who launched a parallel case that was merged with McCord's said they were "deeply disappointed" by the rejection of their case, but had not yet decided whether to appeal.
A judge has dismissed the UK's first legal challenge to Brexit, saying the consent of Northern Ireland's parliament is not required.