Plans to exclude the elections watchdog from assessing the proposed question in a future independence referendum have come under fire during evidence to MSPs.
The question may be rendered not "fit for purpose", a leading referendum expert warned, over a controversial move to exclude the Electoral Commission excluded from examining what Scots are asked if, as expected, this remains the same as 2014.
Professor Justin Fisher of Brunel University London raised concerns as MSPs on Holyrood's Constitution committee took evidence on the planned Referendums (Scotland) Bill which would pave the way for a fresh vote on Scotland leaving the UK. Nicola Sturgeon announced yesterday she is to seek the authority to hold such a vote, perhaps as early as next year.
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But Prof Fisher said: "I think excluding the Electoral Commission from the process at all is inadvisable - so I wouldn't recommend that at all.
"It may well well reduce confidence - that would be pure speculation.
"But in terms of whether or not the question remains fit for purpose, it seems to me that it would be a leap of faith to say that if it worked last time, it must work this time."
"Would there be a time limit between the referendums between when that start of decision would be made? It seems to me to be a little loose with the arrangements to exclude what's a very important part of the referendum process."
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The bill states that, if the proposed question had already been assessed by the commission, it should not have to be assessed again.
This would exclude the commission’s involvement in the same question as 2014 – “Should Scotland be an Independent Country?”
The commission has since ruled out a Yes/No question in the Brexit referendum, instead recommending a Remain/Leave question. This was found to be more balanced after fresh evidence was taken.
A change from Yes/No to a Leave/Remain question could damage the pro-independence movement, with the Yes campaign widely seen as having been successful in conveying a positive message in 2014.
Dr Alan Renwick, Deputy Director of the Constitution Unit, University College London warned that Scotland may have to hold two referendums on independence to avoid the chaos of Brexit. The first would be on the general principle, with a second "confirmatory vote on the "divorce" deal secured with the UK.
He said: "The difficulty of the Brexit referendum and, in terms of structure, an independence referendum is essentially the same.
"It's a referendum on a basic principle, not a referendum on a precisely worked out plan. A difficult clearly arises if people vote for a principle but then the versio of that that is worked out through subsequent negotiations is remote from what was promised during the first referendum.
"My view and the view that was set out by the independent commission on referendums that we ran and reported last year is that if you have a referendum on a broad principle - what we call a pre-legislative referendum - and what was subsequently delivered does not match what was promised, then you ought to have a second referendum.
"And that second referendum ought to be baked into the process from the start so that it's clear to voters what they're actually voting for."