The disciplinary will now not be heard until January 8 at the earliest after the High Court ruled on Thursday that Labour had breached its obligation to ensure fairness.
Mr Greenstein, who is vice-chair of a Marxist group called Labour Against the Witchhunt which challenges the suspension of hard-left party members, said: “All my pleas to the Labour Party to postpone the hearing until the New Year fell on deaf ears.
“Having repeatedly leaked details of my case to the national press, Iain McNicol and the Compliance Unit were determined to expedite my hearing and expel me.
“Despite being Jewish I was suspended as part of the false antisemitism witch-hunt in March 2016. I had evidence that I was being treated differently from other people who were suspended but nothing I said, despite having been in hospital recently, would persuade these people to change their minds.”
Mark MacDonald QC, who has worked in the Palestinian territories and set up the Labour Friends of Palestine and the Middle East group, represented Mr Greenstein.
The Labour Party declined to comment.
The High Court hearing did not consider any of the charges against Mr Greenstein, who had asked for his disciplinary case to be postponed until February.
The JC reported last week that veteran Jewish Labour MP Louise Ellman had been racially abused in blog posts written by Mr Greenstein.
