ONE of the most senior lawyers in Scotland has stepped in after a Spectator columnist accused SNP MP Joanna Cherry of making an “easy mistake”.

Steven Barrett, a barrister who writes for the right-wing magazine, took aim at Cherry on social media as she took part in a Westminster debate on the Safety of Rwanda (Asylum and Immigration) Bill.

He wrote: “Joanna Cherry wrongly using the phrase ‘English law’.

“We don't think of it very often, so it's an easy mistake to make, but the sovereignty of Parliament is UK wide.

“It is thus UK law.”

The post attracted the attention of Roddy Dunlop, a senior KC and the dean of the Faculty of Advocates in Scotland, who branded Barrett’s comments “nonsense”.

Dunlop wrote: “The sovereignty of the Westminster Parliament, however, has not always been treated the same under Scots and English law, which I imagine is the point @joannaccherry was making.

“See MacCormick v Lord Advocate 1953 SC [a case on whether the late Queen Elizabeth could be called ‘the second’ in Scotland]. There isn’t a ‘UK law’ on this.”

Barrett insisted in reply: “We have one constitution. And it's not English law because no one subjugated anyone else, we voluntarily merged the crowns, to forge a new crown.

“That's UK law – for there is nothing else to call it.”

READ MORE: Rwanda plan 'could be subject to Scottish court block', says Joanna Cherry

Dunlop hit back: “Nonsense. Magna Carta is firmly part of your law, and no part of mine. Has it somehow become part of Scots law via osmosis, because of a ‘UK constitution’?

“Your argument ignores the unique and enduring nature of Scots law, including Scottish constitutional law. Read MacCormick.”

Barrett again insisted that Scots and English law had been “merged” by the 1707 Act of Union, leading Dunlop (below) to say: “1953 (MacCormick) is some time after the ‘merger’ (1707), at least according to my calendar.

“Scots law was preserved in 1707 and remains different from the law you practise in. Hence my point re Magna Carta, which proves it beyond any doubt.”

The National:

He added: “The kingdoms merged. But the legal systems did not. Scots law has a different history and content. That includes constitutionally.

“Otherwise, Magna Carta would be part of Scots law and Claim of Right Act 1689 part of English law. That what you’re arguing?”

As an aside, Hansard, the official record of the UK Parliament, does not report that Cherry ever used the phrase “English law” in the debate.

Around the time which Barrett first posted, Tory MP William Cash used the phrase five times, all while quoting from judge and peer Lennie Hoffmann.

Nevertheless, Cherry also responded to the Spectator author, branding his comment “nonsense”.

She added: “Scotland has a separate legal system protected by the Treaty of Union. I will address this in my speech later.”

READ MORE: How did Scottish Tory MPs vote on the Rwanda Bill?

In her speech in the Commons, Cherry raised the issue of whether the Rwanda bill could be open to legal challenge in Scotland due to the effect it could have on Scots courts.

She told MPs: “The bill seeks to oust the jurisdiction of the Scottish courts in relation to such fundamental matters as human rights and the basic tenets of our constitution.

“Scotland’s system of civil justice is a devolved matter under the Scotland Act and therefore the preserve of the Scottish Parliament, yet I do not see any legislative consent motion being sought, despite the fact that the jurisdiction of the Scottish courts is being ousted.

“Perhaps even more importantly – and this is rather important to us Scots lawyers – the authority and privileges of the Court of Session, including its inherent supervisory jurisdiction, are protected by article XIX of the Treaty of Union, which includes the nobile officium of the Court of Session, a power that exists to give remedies where otherwise there would be none. That is arguably also threatened by this bill.”