Kezia Dugdale has moved to clarify her stance on independence after she said in an interview ''it's not inconceivable'' that she could support a future Yes vote if the UK leaves the EU.
Speaking to the Fabian Review, the Scottish Labour leader said she "would very much like'' to remain part of both the UK and EU.
Ms Dugdale was asked where her ''loyalty'' would be if there was an overall vote to leave in the EU referendum but the majority of Scots wanted to remain.
She told the Fabian Review: ''I've never contemplated that. I really wouldn't like to choose, because what I want to do is the best possible thing for Scotland. (I would be) putting Scotland first.''
When pushed on the topic and asked if she would ''argue, for Scotland's sake, against the UK Union?" Ms Dugdale said: ''Possibly. It's not inconceivable.''
Ms Dugdale later moved to clarify her position in a statement, saying: "As I made clear on in the leaders' TV debate this week, Labour has ruled out a second independence referendum. We won't introduce one in government and we would vote against one if it's introduced by any other party.
"I campaigned as hard as anybody to ensure that Scotland remained part of the UK. The collapse in the oil price showed that the best way to secure our public services is to stay in the UK.
"I would vote to stay in the UK in any future referendum."
Independence re-emerged as an election issues during a debate this week.
During the STV programme, Nicola Sturgeon said any future referendum decision was "in the hands of the people", while Tory leader Ruth Davidson accused the First Minister of disrespecting the 2014 poll.
Ms Davidson said Scottish Labour ''simply cannot be trusted to defend the decision of two million Scots to stay part of the UK''.
''The idea that Scotland's place in the United Kingdom is in some way dependent on Britain's membership of the EU is offensive," the Tory leader added.
"Scotland helped build the UK and is an integral part of it - confirmed by the referendum vote just 18 months ago.''
On the campaign trail on Saturday, Ms Davidson will make a speech in Ayr committing her party to "challenge, scrutinize and test" the next government.
Polls suggest the SNP will win a majority in the May 5 vote with Scottish Labour and the Tories competing for second place.
The Lib Dems will focus campaigning in the Highlands over the weekend with party president Baroness Sal Brinton meeting activists and voters in Beauly and Inverness.
The SNP are hosting a series of campaign events across the country, the day after candidate nominations closed for the May 5 vote.
Campaign director and Deputy First Minister John Swinney said: "Only the SNP has the strength, the unity and the vision to keep Scotland moving forward. And Nicola Sturgeon is simply the only credible candidate to lead our country for the next five years.
"Our task as a party is clear. We must all work harder than ever to convince the people once more that we are the best team, that we have the best policies, and that we have the best vision to lead Scotland confidently into the next decade."