Liberal Democrat leader Tim Farron has called on Nicola Sturgeon to join forces in the fight for a second EU referendum to block Brexit.
The First Minister this week hinted she is open to the idea of a second EU poll on the outcome of Brexit negotiations.
Mr Farron said Ms Sturgeon should help “build the case” for a second referendum asking voters whether they want to accept the deal struck with Brussels or remain in the EU.
At their party conference in four weeks ago, the Lib Dems adopted a demand for a second EU referendum as party policy in a bid to keep the UK in the 28-nation bloc.
Ms Sturgeon said there “may well be an argument” for a second referendum once the terms of the UK’s exit from the EU are known.
Mr Farron said he welcomed the First Minister’s comments, adding that he hoped she will “continue to build the case with us that the British people should have their say on the final deal in a referendum”.
He said: “We are calling for an opportunity for the British people to have their say on what comes next. Voting for a departure is not the same as voting for a destination.”
Speaking at a conference on Thursday, Ms Sturgeon claimed Theresa May’s government was aiming for “the hardest of Brexits”. The First Minister said “deeply troubling” signs were emerging on the UK government Brexit strategy which “suggest that we are heading down a road of exit not just from the European Union but the single market”.
Ms May’s advisers have said imposing controls on EU migration and removing the UK from the authority of the European Court of Justice are two of the “red lines” that she will take into Brexit talks with Brussels.
The Prime Minister has ruled out holding a second referendum on the EU, insisting there will be “no attempts to remain inside the EU” and no “attempts to rejoin it by the backdoor”.
Ms May told delegates at the Conservative Party conference in Birmingham this week that the formal process for leaving the EU would be triggered by March 2017, without seeking approval from parliament.
MPs will instead be asked to pass a Great Repeal Bill putting EU regulations into UK statute.