The first poll of Humza Yousaf’s premiership has suggested a shrinking lead for the SNP over Labour, but a sizable bounce in the new leader’s popularity.

A survey by Savanta for The Scotsman of 1,009 people between March 28 and 31 shows the First Minister’s approval rating among the public increasing by six percentage points to a net of -12%, although he remains behind his predecessor Nicola Sturgeon, who boasts a net rating of 10%, and Scottish Labour leader Anas Sarwar (-1%) and former rival Kate Forbes (-2%).

Among SNP voters, Mr Yousaf’s popularity soared compared to the previous poll in February, increasing by 19 percentage points to a net of 20%, while Ms Forbes approval rating dropped 15 points to 5%.

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In every electoral test featured in the poll, however, the lead the SNP enjoys over Labour shrank.

At Westminster, likely to be Mr Yousaf’s first major electoral test as SNP leader next year, the SNP vote dropped by three points to 39%, with Labour’s vote increasing by one point to 33%.

In Holyrood constituencies, the SNP vote dropped four points to 39%, with Labour rising by two points to 32%, while Scottish Parliament list voting saw SNP support rise by one point to 33% and Labour increase by three points to 30%.

Elsewhere, the Conservatives also enjoyed an increase in its vote in all three votes.

At Westminster, the party’s vote increased by two points to 19%, while at Holyrood, the constituency vote increase by one point to 19% and two points to 18% in the list vote.

On independence, 48% of decided voters said they would support leaving the UK, while 52% said they were opposed.

When undecided voters were counted, 47% of respondents didn’t back separation, while 45% did and eight were unsure.

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Responding to the poll, SNP MSP Fiona Hyslop said: “The SNP is focused on Scotland’s priorities and that’s why we continue to top the polls.

“Under the leadership of new First Minister Humza Yousaf, who according to today’s poll has already seen a boost to his personal approval ratings, we are setting out a positive, ambitious vision for Scotland’s future.”

She added: “As an independent country we can use Scotland’s immense natural and human resources to build a fairer, more prosperous nation.

“No wonder unionist parties are so terrified of allowing the people of Scotland to have a say over their future – and that is why the SNP are determined that they will have that choice.”