Under its admission terms, all new EU members must commit to adopt the Euro as their currency. First Minister Nicola Sturgeon has previously said an independent Scotland would join the European bloc.
However a survey by Redfield & Wilton Strategies, for the Daily Telegraph, found 39 percent of Scottish voters are less likely to back independence if it means using the Euro.
The survey, of 1,000 Scottish voters aged from 16 up, also found most Scots want to remain part of the United Kingdom.
If a referendum was held tomorrow, 47 percent said they would vote for Scotland to stick with the UK versus 44 percent who back independence.
In April Alyn Smith, the SNP’s foreign policy spokesman, said the party would “totally” back joining the Euro if required for EU membership.
However Nicola Sturgeon has previously suggested Scotland wouldn’t have to adopt the Euro, in order to join the EU.
Speaking to the Daily Telegraph, top Brussels officials said Scotland would be required to join the Eurozone.
One said: “If you join the club, you have to wear the tie. You cannot wear your own tie.”
The poll found Boris Johnson remains unpopular in Scotland, with 60 percent disapproving of his performance.
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She has pledged to hold a second referendum on Scottish independence, after Scots backed the union in 2014 by 55 percent of the vote to 45 percent.
However, in total pro-union parties got more votes than their nationalist rivals in the constituency poll.
Mr Johnson is arguing against another referendum, instead urging the SNP to focus on Scotland’s coronavirus recovery.
Earlier this month Cabinet Office minister Michael Gove argued there will be a second Scottish independence referendum, if there is “a settled will in favour” of one.
Speaking to the Sunday Mail he said: “The principle that the people of Scotland, in the right circumstances, can ask that question again is there.
“I just don’t think that it is right, and the public don’t think it is right, to ask that question at the moment.
“If it is the case that there is clearly a settled will in favour of a referendum, then one will occur.”
Mr Gove didn’t explain how the “settled will” of the Scottish public would be defined.
The UK is hosting the UN’s COP26 climate change conference in Glasgow later this year.
Mr Johnson will host leaders from around the world as they discuss the battle against climate change.