The UK Supreme Court on 24 January 2017 uphold in a highly awaited decision the decision of the High Court in London finding that the UK government cannot trigger Article 50 TFEU without an act of Parliament authorizing that course. The Parliament approved in 1972 the legislation enabling the UK to join the EU, thereby incorporating EU Law into national law. The Court however ruled that no separate approval from the regional legislatures in Northern Ireland, Scotland and Wales was needed.
See our previous post on the decision of the High Court in London: Link
The jugdment is available online: Link