Academic fears Brexit could cause Scots 'constitutional crisis'
An academic from the Institute for Government has predicted that Brexit could cause a "constitutional crisis" within the UK.
Akash Paun told Holyrood's Europe committee that the Scotland Act may need to be revisited due to Brexit "cutting across" devolved areas.
MSPs are studying how leaving the EU will affect Scotland.
The UK government has said the devolved parliaments will be consulted on the Brexit deal but will not have a "veto".
Mr Paun, a fellow of the independent research group, was questioned about Scotland's future intergovernmental relationships alongside fellow academic Prof Nicola McEwen, of the Centre for Constitutional Change at Edinburgh University.
The committee has been pressing for details of how Scotland will be involved in the Brexit negotiations, with Theresa May pledging to "consult" devolved administrations but refusing to give a "running commentary" on how this will work.
Scotland's Brexit minister Mike Russell has said he expects a formal process for Scotland's input to be announced soon.
But Mr Paun said the Brexit process was "likely to reopen far more elements of our internal territorial constitution than anyone has quite got their heads around yet", and warned that the legislation setting out Holyrood's powers may need to be reassessed.
He said: "We may come out of this with a very different set of constitutional arrangements both for governing the distribution of powers between different governments and also in areas where the UK takes back competence from Brussels.
"We may need new arrangements for coordinating policy between the levels of government as well.
"I think the UK government certainly hasn't quite realised the whole box of issues that this opens up.
"I think it's pretty much inevitable that the design of the constitutional settlement and the Scotland Act will need to be revisited as part of this process.
"Some people have wondered if you could simply remove the reference to EU law or go for a minimal approach like that, but because of the nature of our membership of the EU winding its way through almost every area of domestic policy, by pulling out it's going to fundamentally change the individual devolution settlements and the relationship between the nations of the UK."
Prof McEwen agreed that Brexit might need primary legislation like the Scotland Act to be "looked at again".
While the UK government has ruled out the devolved administrations having any "veto" on the triggering of Article 50 - the formal process of leaving the EU -Mr Paun said they may be called upon to give consent at a later stage.
He said: "At the end of the process, when some form of Brexit deal is implemented, at that point I very much expect we'd see legislative consent motions put before probably all the three devolved legislatures, because Brexit will cut across devolved areas and change the competencies, pretty much inevitably, of the devolved institutions.
"As we know that is probably not judicially enforceable, so I don't think that gives the Scottish Parliament a veto over Brexit.
"But I think it would be in breach of established convention for the UK government to push ahead with something that changed the constitutional settlement of Scotland radically without reaching agreement on the terms of that."
Asked by convenor Joan McAlpine if this would cause a "constitutional crisis", Mr Paun replied "probably, yes".
At the same meeting, Prof McEwen told MSPs that Scotland was likely to need consent from the UK to hold talks with EU member states during the Brexit process.