“@Keir_Starmer Stands for nothing but #Purge of socialists and following commands from Israel,” he wrote.
The Jewish Representative Council of Greater Manchester and Region said the comments were “overtly antisemitic” and must be “condemned in the strongest possible terms.”
The local Jewish group praised Labour for the “swift and decisive manner in which this case has been handled.”
Southend councillor Matt Dent was among Labour figures condemning Mr Cooper’s tweet, alleging it contained "an antisemitic trope."
A Labour spokesperson said the party "takes all complaints seriously and they are fully investigated in line with our rules and procedures, and any appropriate action is taken."
Mr Cooper was elected in 2018 with a 72 per cent share of all votes cast. He was contacted for comment.