THE UK Government has mounted a controversial legal challenge to two Holyrood Bills, arguing parts of them are unsound and encroach on Westminster sovereignty.

The UK law officers today referred the Bills - on children’s rights and local government - to the UK Supreme Court for a ruling on their competence.

Deputy First Minister John Swinney called the challenge to the children's rights bill "morally repugnant" and said he would see the UK Government in court.

The referral means the Bills, which were both passed unanimously by MSPs last month, will not receive royal assent and become law until a decision is delivered.

The Supreme Court justices can either uphold the Bills or refer them back to Holyrood to be amended.

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Until now, only one other Bill has been referred to the court in the history of devolution.  

That was in 2018 when Holyrood passed a Bill about the continuity of EU laws after Brexit.

The Court found the Bill was largely valid when passed, but the pause let Westminster pass other legislation which rendered it defunct.

The latest move follows a warning from Scottish Secretary Alister Jack last month that the legislation may be flawed - a move the Scottish Government called a “blatant power grab”.

The Bills both incorporate outside standards into Scots law - the United Nations Convention on the Rights of the Child and the European Charter of Local Self-Government.

The UNCRC Bill is intended to give enhanced legal protection to children by obliging public authorities to respect their rights and comply with UNCRC requirements.

The UK Government has objected to sections 6 and 19 to 21 of the Bill.

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It says Section 6 seems to place obligations on UK ministers acting in reserved policy areas in Scotland, while 19-21 limit the UK Parliament’s absolute right to make laws for Scotland. 

Mr Jack asked the Scottish Government to amend the sections before the Bill went to final vote, but Mr Swinney refused, calling the request “menacing”. 

Mr Swinney and Nicola Sturgeon have both condemned the UK Government’s request in the Holyrood election campaign, fuelling suspicions in Whitehall that SNP ministers cynically refused to change the law, despite possible problems, in order to generate a political row.

The UK Government has also objected to Sections 4 and 5 of the European Charter Bill, which was introduced by former Green MSP Andy Wightman with the aim of protecting the basic powers of local authorities. 

The UK Government argues the sections would constrain Westminster’s ability to make laws for Scotland. 

Responding to the development, Mr Swinney said: “The [UNCRC] Bill is a massive shift in power out of the hands of ministers and into the hands of children themselves.

“It passed unanimously. And, crucially, it has been certified independently by the Presiding Officer as being within the powers of the Scottish Parliament.

“Now, the Tory Westminster government is trying to veto those rights. That is not just morally repugnant but it is also deeply menacing.

“The only people who need fear this Bill are people who want to breach children’s rights.

“The only people who want to block this Bill are people who know they are already breaking those rights.

“So, if the Tories want to target the rights of Scottish children, then they can expect to see us in court.”

Scottish Labour leader Anas Sarwar said: "The Conservatives are bereft of compassion and have completely lost their way.

"At this time of national crisis, we should be pulling together to build a fairer Scotland, not playing petty political games. Scotland deserves a better opposition."

A UK Government spokesperson said: “UK Government Law Officers have today referred two bills from the Scottish Parliament to the Supreme Court under Section 33 of the Scotland Act 1998.

“The UK Government Law Officers’ concerns are not about the substance of the legislation, rather whether parts are outwith the legislative competence of the Scottish Parliament.”