Four Socialist Party members are facing expulsion from Unison or a ban on holding Unison office.
Disciplinary hearings are being held against Glenn Kelly, Onay Kasab, Suzanne Muna and Brian Debus.
The disciplinary investigation was instigated a year and a half ago and the four have already faced a three-day hearing in May 2008.
The date for the next hearing is: Wednesday 18 March at the Holiday Inn, Regents Park, Carburton street, London W1. A lobby will take place from 8.30am. Please bring placards and banners.