The Times reports that senior SNP figures want a Norway-style model enabling an independent Scotland to remain in the single market via the European Free Trade Area and European Economic Agreement.
Scottish Liberal Democrat leader Willie Rennie claimed the move was aimed at appeasing Yes voters who want to leave the EU while “abandoning” those who voted to remain.
He said: “By abandoning full membership of the EU it is clear the SNP are crudely attempting to buy off the hundreds of thousands of Brexit supporting Yes voters. Yet with this act they are also abandoning 1.6 million people who voted to stay in the European Union.
“The SNP are using the remain voters to demand an independence referendum but are quick to sell them out to keep the independence movement unified.
“They know that many Brexit voters would not back independence if it meant rejoining the EU. So they ditch Europe to make gains on independence.
“If Scotland were to leave the customs union we would not have the same benefits that we have enjoyed as a member of the EU. An independent Scotland being semi-detached from both the UK and the EU would make Brexit look like a picnic.
“Liberal Democrats stand wholly, unapologetically committed to both the UK and EU and want Scotland to stay in both. Unfortunately it looks like the SNP want neither.”
Scottish Conservative leader Ruth Davidson said the SNP needs to “get back to the day job”.
She added: “None of this is about getting the best deal for Scotland.
“All it is about is a narrow nationalist obsession with breaking up this country against the wishes of the Scottish people who’ve said they want to stay part of Britain.
“I think Nicola Sturgeon needs to take a long, hard look at herself because we saw over the weekend there are only 27 per cent of Scots that have said they fancy going for an early indy ref, which is what she is threatening.
“She needs to get back to her day job and spend less of her time concentrating on another independence referendum that the majority have no truck for.”