Scottish voters would vote for independence from the U.K., according to a poll by Michael Ashcroft, the first major published survey to show a lead for independence since March 2017.

Asked how they would vote in an independence referendum, 46% of the 1,019 surveyed voters said they would vote for independence and 43% against. Excluding those who said they did not know or would not vote, this amounted to a lead of 52% to 48% for an independent Scotland.

"In the wake of [Prime Minister] Boris Johnson's visit to Edinburgh last week I polled Scots to measure support for a second independence referendum and to gauge opinion on independence itself," Ashcroft, a Conservative who opposed Johnson's leadership, said. "I found a small majority in favor of a new vote, and the first lead for an independent Scotland for more than two years," he said.

Relations between Edinburgh's devolved government and former Prime Minister Theresa May's Conservative government were strained after the Brexit referendum in 2016. While 52% of U.K. voters opted to quit the EU, in Scotland, 62% voted for Britain to stay in the 28-country bloc. Immediately after the Brexit vote, Scottish First Minister Nicola Sturgeon said a second independence referendum was now on the table; however, any binding vote on Scottish secession must take place via a so-called Section 30 order granted by the British parliament.

In 2017, May declined to give permission for such a vote, while Brexit was going on. In September 2014, Scots voted 55% against Scotland becoming an independent country and leaving the U.K.; support for independence was at around 45%, although polls had shown increasing Scottish opposition to May's Brexit plans.