The SNP must “get off the fence” and back a referendum on the final Brexit deal, Liberal Democrat leader Vince Cable will say.
Mr Cable will urge Nicola Sturgeon to support a vote on the terms of the UK’s deal on leaving the European Union (EU).
The SNP leader has said that while the case for a second EU referendum may become “irresistible” it is not her party’s policy.
Mr Cable will focus on the “threat” Brexit poses to Scottish businesses on a visit to Edinburgh with Christine Jardine MP and Alex Cole-Hamilton MSP.
He is expected to say: “The collapse of the pound means Edinburgh airport may be soaring but a huge majority of Scottish firms recognise that Brexit will be bad for business.
“At the moment, the Government’s transition period only delays Britain from falling off the cliff edge given the hard Brexit that the Tory right is determined to pursue.
“Businesses in Scotland need the SNP to get off the fence and say whether they will back a referendum on whatever terrible deal Theresa May brings back from Brussels.”
He will add: “It is not enough for Nicola Sturgeon to say that a referendum on the final deal is not SNP policy at this time. It is this time and this moment that matters.
“She needs to be clear now with businesses and the wider public as to whether she will give them the chance of an exit from Brexit.
“The Liberal Democrats are the only party speaking out on behalf of the majority of Scots who are pro-UK, pro-EU and progressive.”
SNP MP Peter Grant said: “It is extraordinary that as the Tories are dragging Scotland and the rest of the UK closer to the cliff edge of an extreme Brexit, all the Lib Dems want to do is attack the SNP.
“We have been utterly consistent in supporting continued membership of the single market and customs union - and instead of trying to undermine consensus Vince Cable should instead be turning his fire on Labour for their shameful failure to stand up to the Tories’ Brexit shambles.
“Scotland voted to remain in the EU referendum and the SNP still believe staying in the EU is the best option. The Lib Dems, as with the Tories and Labour party, haven’t given any guarantees that if Scotland was to vote for a second time, that we wouldn’t still be dragged out of the EU against our will.”