A former Scottish Secretary has said an independence vote during Brexit negotiations would be illegitimate.
Alistair Carmichael, the Lib Dem MP who headed up the Scotland Office during the 2014 referendum, also questioned the Prime Minister’s credibility to campaign effectively against a Yes vote.
He spoke as delegates arrived in Perth for the start of a two-day Scottish Liberal Democrat conference.
Mr Carmichael, who represents the Orkney and Shetland at Westminster, said it would be wrong to have a vote in 2018, as championed by senior SNP figures, because the UK would still be in separation talks with Brussels.
He told The Herald: “It is difficult to see how you can legitimately ask the people in Scotland if they want to leave the UK when it is not yet clear what sort of UK you would be leaving.”
Mr Carmichael, whose party is against another Scottish independence referendum, wants the UK public to get another vote on the deal that Mrs May extracts from the EU.
On independence, he said he fears the PM will revert back to the Project Fear tactics of 2014, when any repeat campaign would have to be “much more Scottish-centric”.
Nicola Sturgeon said this week a referendum in autumn 2018 would be a “common sense time for Scotland to have that choice, if that is the road we choose to go down”.
But the First Minister added there is still time for the UK Government to find a compromise with her government that would respect Scotland’s Remain vote.