SNP leader Nicola Sturgeon has been dealt a new blow after a post-EU referendum poll showed the majority of people in Scotland favour remaining in the UK. The YouGov survey comes a month after the UK voted 52% to 48% to split from the EU.

Northern Ireland and Scotland voted to remain in the 28-nation bloc, fuelling speculation of a second Scottish independence referendum. But the online YouGov poll, of more than 1,000 adults in Scotland between 20 and 25 July, showed 53% of respondents wanted to remain part of the UK, while 47% wanted Scotland to split from England, Wales and Northern Ireland.

YouGov said the latest results show "little difference" since the pollster last researched the issue ahead of the EU referendum in May, when 54% of Scottish voters wanted to stay in the UK and 46% backed independence. A 2014 referendum on the issue saw 55% of Scots rejecting a split from the historic union, while 44% backed a breakaway.

"Inevitably, some will suggest that the high-water mark of Scottish independence has now passed, especially as it was thought that leaving the EU might persuade 'No' voters to change their minds and vote against the Union," said Joe Twyman, YouGov's head of political and social research.

"However, the situation is, naturally, more complicated than that. There remains a great deal of uncertainty about what the UK's relationship with the EU will look like in the long term.

"A lot could, and almost certainly will, change on this front in the coming years. For example, Article 50 has not yet been triggered and once precise details of Brexit are hammered out it could change the whole context of the independence debate – in either direction.

"Ultimately it is unclear what the medium- and long-term impact of Brexit on people's livelihoods will be and therefore it is also unclear on where Scottish public opinion will go. But in the short-term at least, the data suggests the vote to leave the EU has not boosted the cause of Scottish independence."

Sturgeon, who became first minister of Scotland in November 2014, recently warned the UK was heading towards a "hard exit" from the EU.

The SNP leader has promised to "keep all of our options open" ahead of new Prime Minister Theresa May triggering Article 50 of the Lisbon Treaty. Sturgeon has assembled a team of experts, including legal, diplomatic and economic advisors, to help her government.