Race storm erupts after Andrea Riseborough’s best actress Oscar nomination

The Academy Awards has found itself at the centre of race row after Andrea Riseborough's unexpected nomination for a best actress Oscar for her performance in To Leslie, seemingly at the expense of Viola Davis for The Woman King and Danielle Deadwyler for Till.

Social media has also seen a revival of the #OscarsSoWhite hashtag which first achieved prominence in 2016 after no non-white actors were nominated in any of the performance categories.

Riseborough's Oscar nomination came largely out of the blue, as she had only rarely featured earlier in the awards season; on the other hand, both Davis and Deadwyler were nominated for the Screen Actors Guild awards, and Davis for the Golden Globes. Riseborough's only prior nomination of significance is for the Independent Spirit awards, to be announced in March. However To Leslie's profile was raised by a concerted campaign involving significant numbers of A-list actors, including Edward Norton, Charlize Theron, Jennifer Aniston and fellow Oscar nominee Cate Blanchett, who either hosted screenings and Q&As, namechecked Riseborough at awards ceremonies or posted on social media. To Leslie's campaign was assisted by two PR companies, Narrative and Shelter, and appears to be self-funded, while Till and The Woman King were backed by deep-pocketed studios United Artists and Sony respectively.

The Academy of Motion Picture Arts and Sciences (Ampas), the body that organises the Oscars, announced that it will meet on Tuesday to "review" its campaign regulations, saying it wanted "to ensure that no guidelines were violated, and to inform us whether changes to the guidelines may be needed in a new era of social media and digital communication".

Ampas guidelines on campaigning stress that it should be "conducted in a fair and ethical manner" - for example limiting the number of screenings that can be held, defining the kind of hospitality that can be offered, and banning nominees from contacting Oscar voters directly.

The success of the campaign on behalf of To Leslie also appears to have backfired on Riseborough herself, with Variety quoting an anonymous Academy member saying: "No matter what happens, her reputation is being tarnished, whether her campaign did something or not."