The committee’s fourth report, published today, focusses on the impact of Brexit on devolution.

It calls on the UK government to “respect the particular circumstances in Scotland”, including the high level of support in Scotland for remaining in the EU, but warns that keeping Scotland in the single market would be politically impracticable, legally complex and economically disruptive.

The report suggests “differentiated arrangements could be reached in fields such as energy policy, justice and home affairs cooperation, participation in Europol, access to EU structural or research funds, participation in such programmes as Horizon 2020 or Erasmus, reciprocal healthcare provision, workers’ rights and working hours, and agriculture and fisheries”.

However, it says it is “not possible at this stage to reach definitive conclusions” because of uncertainty over the Brexit negotiations.

Dr Nick McKerrell, lecturer in law at Glasgow Caledonian University, told Scottish Legal News: “This report actually goes a long way to recognising the Scottish Government’s past position of a differential settlement for Scotland within Brexit. The caveat is that they believe this would only be the case if the Brexit negotiation package is viewed as not suitable, presumably at the end of the process. Thus they make it clear they want the Scottish Government to be involved at the heart of Brexit.

“Interestingly the report suggests that a number of areas that are devolved could fit into differentiated solutions. For example, our independent criminal justice system could make an agreement over European Arrest Warrants regardless of the position of England. Also, as the Scottish Health service is run up here, there could be a separate agreement on access to healthcare across the EU.

“The problem comes when a step up is made to other powers which would require to recognise Scotland as a state within international law. This would indeed be unprecedented and ‘unpredictable’ because in international legal terms, the state that we are a part of is the UK. Thus any negotiations have to be carried out in the name of Britain. This would clearly become relevant if more contentious issues – like a different Scottish approach to immigration – were up for discussion.

“The report is pretty vague on where the line could be drawn on issues that would require this ‘full state’ status – even in areas that are clearly independent in Scotland like criminal law and the health service. It is ultimately inconclusive but at least it recognises the possibility of Scotland having different relations to some aspects of the European Union than England post Brexit.”

Lord Jay of Ewelme, a member of the Lords EU Committee and former Head of the Diplomatic Service, said: “Brexit’s impact on the future of the United Kingdom will be profound and unpredictable. At the moment the internal politics are pretty toxic, and we saw only last week the start of what could become a deep and bitter dispute on the role of the devolved institutions in passing the EU (Withdrawal) Bill.

“We can’t afford this. The UK Government must respect the devolved institutions. It’s not enough saying it’s listening to them—it’s actually got to take account of what they say and adjust its approach to accommodate their specific needs. Equally the devolved administrations must work with, not against, the UK Government to get the best Brexit for the whole of the UK.

“Devolution in the UK has been uncoordinated. For the last 20 years the EU and its institutions have helped hold together an increasingly devolved UK. In the long term we will need real reform: we will need to agree guiding principles, and finally replace the Barnett Formula with a needs-based funding arrangement.

“But that’s for the future. In the short term what is crucial in getting the best out of Brexit for all parts of the UK. That means setting aside party politics and working together. It means the Government getting the basics right, using existing structures like the Joint Ministerial Council on European Negotiations to build a true consensus.”