Humza Yousaf has been elected the first minority ethnic leader of the Scottish National party, in a narrow victory that will force him to confront deep divisions within the party. He is almost certain to be confirmed as Scotland’s next first minister after the Scottish Greens said they would back his nomination on Tuesday, but he faces a significant internal challenge bringing the SNP’s warring wings together. Widely seen as Nicola Sturgeon’s preferred successor, Yousaf defeated his closest rival, Kate Forbes, by a narrower than expected 52% to 48% after second-preference votes cast by supporters of Ash Regan, the candidate who came last in the first round, were counted. The turnout was 70%. He secured fewer of Regan’s second-preference votes than Forbes but took enough to win. Even so, the size of Forbes’s vote demonstrates that Sturgeon’s policy platform has less support among ordinary members than thought. In the first round, Yousaf led with 48% of the votes, with Forbes on 40%. Forbes, a social and fiscal conservative, founded her campaign on blunt and highly critical attacks on Yousaf’s record as a minister, in which she denounced his repeated support for Sturgeon’s centre-left policies as “mediocre” and complacent. In an immediate boost to his nascent government, the Scottish Greens said they would vote to confirm Yousaf as first minister on Tuesday and would uphold the Bute House power-sharing agreement brokered by Sturgeon in 2021. That will maintain a pro-independence majority at Holyrood and ensure Yousaf can push through future budgets and policies without negotiating with Holyrood’s three pro-UK parties. Over the weekend, the Scottish Greens warned that the SNP would risk becoming a minority government if Forbes won, as they would abandon the coalition. In a signal to the SNP’s independence hardliners, Yousaf told ITV News that one of his first acts as first minister would be to formally request the powers to stage a fresh independence referendum from the Westminster government – a request Downing Street rejected. Yousaf said he would immediately meet Forbes and Regan to discuss keeping them in the government. Regan resigned as a junior minister in protest at Sturgeon’s gender recognition reform bill – legislation Yousaf has pledged to defend. Forbes, too, was highly critical of those reforms. Yousaf had taken his seat before the official announcement with a grin on his face, having high-fived some of his supporters. He said he wanted to unite all sections of the party. The size of Forbes’s support suggests he may need to rethink many of his boldest taxation policies in order to keep her in his cabinet. “Leadership elections by their nature can be bruising; however, in the SNP we are a family,” Yousaf said. “Where there are divisions to heal, we must do so quickly because we have a job to do and as a party we are at our strongest when we are united.” Forbes, the finance secretary, who is due to return from maternity leave in early April, told reporters after Yousaf’s speech that she would discuss staying in his cabinet but refused to say what she would want in return. She made clear she expected him to listen to party members, and she would not commit to backing Yousaf’s policy of fighting the UK government’s block on Holyrood’s gender recognition bill. Securing 48% of the vote may make Forbes consider running again for the leadership in future. Many opinion polls suggested Scottish voters preferred her to Yousaf, although those polls also showed most voters were unsure who would be the best first minister. Forbes said she was a democrat, adding: “I’m here to support the new leader of the SNP. I absolutely accept Humza Yousaf is the new leader and of course I will continue to work with him to ensure we have a plan which has the confidence of SNP members.” She said she expected Yousaf to accept that discussions about the SNP’s policies and direction had to continue now the leadership contest was over – a strong hint she wants him to compromise on his policies. “We’re absolutely united [but] we want to create the opportunity in the party now to continue to discuss ideas, but we are united as one, to serve the people of Scotland,” she said. The announcement at Murrayfield stadium in Edinburgh on Monday afternoon came after a fractious contest involving deep policy divisions, unprecedented personal attacks and the resignation of the party’s chief executive and Sturgeon’s husband, Peter Murrell, after damaging revelations that the media had been fed false information about membership figures. The party revealed that its membership had fallen from 104,000 to 72,000 since December 2021 after Yousaf, Forbes and Regan demanded transparency in how the vote was being run. The result was announced after the online ballot of members closed at midday, concluding the first leadership contest since 2004, as Sturgeon was elected unopposed to replace Alex Salmond in 2014. At the end of his victory statement, Yousaf paid tribute to his Punjabi grandparents, who arrived in Scotland as migrants in the 1960s speaking rudimentary English. His grandfather Muhammad Yousaf worked in a sewing machine factory; his grandmother Rehmat Ali Bhutta stamped tickets on Glasgow buses. “They could not have imagined in their wildest dreams that their grandson would one day be on the cusp of being the next first minister of Scotland,” he said.