The Scottish Labour leader, Anas Sarwar, has said he agrees with Angela Rayner that Diane Abbott should be allowed to stand for the party at the general election. His comments came as splits were emerging among senior party figures, with Rayner, the deputy Labour leader, telling the Guardian Abbott had not been treated “fairly or appropriately” by some Labour colleagues and she “doesn’t see any reason” why Abbott could not run now the party whip had been restored. The London mayor, Sadiq Khan, the shadow health secretary, Wes Streeting, and the shadow home secretary, Yvette Cooper, have also expressed some form of uneasiness with the party’s treatment of Britain’s first black female MP. But the shadow science secretary, Peter Kyle, said the general election was “about the future” and the national executive committee (NEC), the body that decides who will represent Labour, “will be making sure our party is fit for the future”. Some Labour figures see Rayner’s comments as unhelpful, but Sarwar’s backing will put further pressure on Keir Starmer. Sarwar told BBC Breakfast: “I would agree with Angela that Diane Abbott is someone who’s a historic figure in our party, a trailblazer, and someone who has a record of service for our party.” He added: “The article that Diane Abbott wrote which was not acceptable, which led to a disciplinary investigation, an investigation that has now concluded … We’ve had the disciplinary process, she’s had the whip restored, it’s now for the NEC to do the endorsements of candidates, and I hope people will recognise Diane Abbott is a trailblazer, someone with a strong history in the Labour party, but ultimately that’s a decision for the NEC.” Starmer has refused to say whether or not he would like Abbott to stand for the party at the next election, saying it would be a matter for the NEC. He is facing mounting accusations of “purging” those on the Labour left before a crunch NEC meeting next week to finalise Labour’s full list of parliamentary candidates. Kyle said Labour had attempted to conduct the investigation into Abbott’s remarks “in a way which is dignified”, and that “what we’re doing is making sure our party and everybody who represents it, represents the Labour party in the 2020s, facing forward”. Speaking to Times Radio, he said of Abbott: “She’s a trailblazer … but where we are at this moment in time is about facing the future, and the NEC will be making sure that everybody who stands for us meets the high standards that Keir Starmer has set for the Labour party.” Abbott this week said she had been barred from standing as a Labour candidate but has vowed to stand again “by any means possible”. Lenny Henry and David Harewood were among leading black British actors, professors, authors and broadcasters who condemned Labour’s treatment of the veteran MP on Thursday night, as “disproportionate, undemocratic and vindictive”. In an open letter, also signed by Reni Eddo-Lodge, Misan Harriman, Afua Hirsch, Jackie Kay, Linton Kwesi Johnson, Adrian Lester and Gary Younge, they said: “Just last Friday he said the investigation into her conduct had not been resolved even though Abbott had satisfactorily completed the disciplinary process in February. Indeed, the fact that the party reached its conclusion several months ago and failed to readmit her to the parliamentary party until earlier this week, after the story broke, indicates a determination to humiliate her. “Coming from a community where discrimination is a daily reality, we know unfairness when we see it.” Martin Forde KC, the senior lawyer commissioned by Starmer to investigate allegations of sexism, racism and bullying in Labour, said the party had been “underestimating” the impact its treatment of Abbott and Faiza Shaheen was having on voters. Shaheen, who has been barred by Labour from standing again in the Chingford and Woodford Green constituency, said she intended to challenge the decision, claiming she had faced “a systematic campaign of racism, Islamophobia and bullying”. Labour has already selected a replacement candidate in Chingford and Woodford Green, Shama Tatler.