A LEADING European lawyer has warned Westminster’s post-Brexit power grab could spark a severe constitutional crisis and accelerate Scottish independence.

Stephen Phillips, a partner and member of the Brexit Group at law firm CMS, says the UK Government’s plans for an internal market could trample over Scots law and would represent a “major reversal of devolution”.

In an article published by the Scotsman, he says Westminster’s proposals seem to be an attempt to replicate the EU single market within the UK. However, given the lack of detail provided so far, the lawyer says he shares Holyrood’s fears about the potential effect on the devolution settlement.

He explains: “The proposal’s aim of creating a system of ‘mutual recognition’ appears to replicate the minimum standards that underpins the freedom of movement of goods in the single market but there are major differences.

“In the EU system, no member state is powerful enough to dictate standards and there is a complex oversight system involving the EU Commission, Council of Ministers, national governments, and the European Parliament to create broad consensus. The same cannot be said of the UK system, due to the disproportionate strength of the English market and likely unwillingness of the Westminster Government to agree to a consensual system involving the devolved administrations. Practically, this could potentially result in lower standards, agreed by Westminster to secure global trade deals, being forced on devolved nations.”

Phillips warns that if lower standards are enforced it could end up tarnishing Scotland’s reputation for excellence in food and drink, which is vital to the country’s exports and economy.

He continues: “Westminster hegemony over these matters would also adversely impact aspects of Scots law which, rather than remaining innovative and reflecting Scottish concerns, would merely become a rubber stamp of English law.”

Phillips gives the example of minimum unit alcohol pricing, which the US government has already flagged as a possible obstacle in a future trade deal with the UK. “There is a real threat to this and other areas determined by Scottish law that would be overridden by the UK Government to secure such an agreement,” he explains.

READ MORE: Brexit power grab: MSPs demand a say on UK internal market plan

The lawyer says that such fears could be allayed were Holyrood to be given a meaningful say in the process, as has been the case with Quebec influencing Canadian deals or the Flemish in Belgium. He adds: “Unfortunately the mood music currently emanating from Downing Street is that Holyrood will have no meaningful role.”

Phillips continues: “There are fears the UK Government or one of its agencies will have the right to challenge and invalidate Scots legislation, a development that until now had been restricted to the UK Supreme Court on normally very limited human rights grounds.

“Making aspects of Scots law irrelevant would represent a major reversal of devolution and create a major constitutional crisis which threatens Scotland’s long term future in the Union.”

The UK Government insists the proposed internal market "will ensure the free flow of goods and services across every part of the UK, while upholding the devolution settlement".

A spokeswoman added: "This will give the devolved administrations power over more issues than they have ever had before, without removing any of their current powers."

However, Michael Russell Scotland’s has condemned the move as a Westminster power grab.

Scotland’s Constitution Secretary said the proposed legislation would mean the UK Government "have a veto on everything".

Warning the Scottish Government is considering legal action to challenge the plans, he said: "This is an outrageous power grab and it is a major weakening of devolution, and it should not be permitted to take place.

"My view is that it reveals completely the agenda of the current UK Government, which is hostile to devolution and hostile particularly to Wales and Scotland for exercising their rights under devolution."