Scottish Labour leader Richard Leonard has said his party should have a clear policy to remain in the EU.
Speaking on the Sunday Politics Scotland programme, he said “clarity” was need before Labour put its case to voters.
The Scottish government has, meanwhile, asked for further funding to cope with a possible no-deal Brexit.
The UK government said money would be available where Scotland faces disproportionate costs.
In his television interview, Mr Leonard called for Labour to say its preference was to remain in the European Union.
“We recognise there are parts of the UK – and the overall result was to leave,” he said.
“But I do think that we need clarity in our position.
“So you would expect me to be arguing, as I am, that means we need to be clearer in our position going into any public vote.”
Mr Leonard added: “The Scottish Labour party took a decision frankly in the wake of the European party election results that we needed to be much clearer, that we needed much greater clarity about the position that we were taking.
“For that reason the Scottish executive of the Labour party backed my proposal that we call for an affirmative vote that any deal should go back to the public; secondly, that on that vote there should be a remain option; and thirdly, that we would campaign unambiguously for remain.”
His comments came as the Scottish government said more money would be needed if the UK crashed out of the EU without a deal.
It has requested £52m from a contingency fund to prepare for a no-deal Brexit.
Money from the EU Exit Operational Contingency Fund has been made available ahead of Britain’s departure from the European Union on 31 October.
Finance Secretary Derek Mackay reiterated the Scottish government’s opposition to any form of Brexit.
He also asked that additional costs associated with it are met including those beyond the end of next month.
Mr Mackay said: “The UK government now seems to be actively pursuing a ‘no-deal’ outcome which is utterly unacceptable and must be avoided at all costs.
“We have requested £52m from the UK government’s fund to help us prepare for a ‘no-deal’ outcome.
“This is the minimum requirement for operational activity but the real costs of a ‘no-deal’ Brexit will massively outweigh these and further funding will be required.”
He also said leaving the EU was not Scotland’s choice and called for any related costs to be covered by the UK government.
Mr Mackay added: “The Scottish government should not have to cut spending on public services to fund Brexit preparations.
“As a responsible government, we are already taking steps to protect jobs and our economy from a ‘no-deal’ Brexit and we will set out those plans to parliament shortly but we are facing additional and disproportionate costs to mitigate the impact of such an outcome.
“We will continue make the case for staying in the EU and will stand firm against efforts to take us out against our will.”
The request includes funding to support the effect of no-deal on rural communities, increased demand on Marine Scotland and Police Scotland activities, additional communication to EU citizens in the country, and poverty mitigation measures.
‘Supporting a deal’
A Scottish Conservatives spokesman said: “In 2016, the UK electorate voted to leave the EU.
“Only the Scottish Conservatives have worked to prevent no-deal by supporting a deal.
“The SNP were given £92m for our councils to prepare for Brexit.
“Yet there is no evidence Scottish local authorities have received anything at all.”
It comes after Scotland’s chief economist on Friday predicted a potential £2bn loss of investment because of Brexit.
Forecasts up to April 2020 in the Scottish government’s quarterly State of the Economy Report show £500m of investment could be wiped out if uncertainty continues with the figure rising by the end of the year.
A spokeswoman for the UK government said: “We have allocated the Scottish government nearly £140m in funding for EU exit preparation.
“We will consider the Scottish government’s further bid under the £1bn Operational Contingency Fund in the usual way.”