From what I know, and have been told, Starmer basically gave an instruction to clear the backlog of anti-Semitism suspensions as quickly as possible.
Under the current rulebook, passed by conference, if I was to openly post something anti-Semtiic on social media, I would be auto-suspended and the investigation would be fast tracked:
https://labour.org.uk/wp-content/up...atistics-Report-No-Place-For-Antisemitism.pdf
However, if for example it could be proven that I campaigned for another political party, or supported ideas incompatible with the Labour Party, I could be expelled without a hearing.
There was a trawl of suspended members social media history, and the Party used what they found (previous membership of the SWP, openly supporting the Greens etc) as a way of getting rid of people without appeals and reducing the backlog.
Previously, under Corbyn, head office was relaxed about people joining Labour who may have been members of TUSC or the SWP very recently. Their attitude was that if MPs can cross the floor and change affiliation, it is only fair that members can do the same.