In March, Holyrood unanimously passed the United Nations Convention on the Rights of the Child (Incorporation) (Scotland) Bill, which would incorporate a UN treaty into Scottish law.
Scottish Secretary Alister Jack raised concerns the legislation could potentially put legal duties on UK Ministers, which would be outside the remit of the Scottish Government’s power.
However, after the legislation was not amended, Mr Jack said the issue would be referred to the Supreme Court.
The legal bid, starting on Monday and brought by the Attorney General and the Advocate General for Scotland, will evaluate whether certain parts of the Bills are outside of the power of the Scottish legislature.
The European Charter of Local Self-Government (Incorporation) (Scotland) Bill, which was also passed unanimously by MSPs, was also referred over similar concerns.
The UK’s highest court will now consider the Bills, which incorporate international treaties that the UK is a signatory into Scottish law.
Over two days, the Supreme Court will also consider whether the Bills would allow the Scottish courts extensive powers to scrutinise legalisation passed by the UK Parliament.
Scotland’s Lord Advocate, the position newly held by Dorothy Bain QC, and Wales’ Counsel General are responding to the legal action.
First Minister Nicola Sturgeon previously called the move “morally repugnant” as the SNP accused the UK Government of trying to strike down a law to protect the rights of children.
However, Mr Jack has repeatedly stated the issue with the legislation is purely based on the possible overreach of the Scottish Parliament, not the contents of either of the Bills.
The case will be heard by five Supreme Court justices and is expected to end on Tuesday, with judgment reserved until a later date.
Reporting by PA