To meet or confer with a mediator, as defined in section 23C of chapter 233, with respect to any litigation or decision on any public business within its jurisdiction involving another party, group or entity, provided that:
- any decision to participate in mediation shall be made in an open session and the parties, issues involved and purpose of the mediation shall be disclosed; and
- no action shall be taken by any public body with respect to those issues which are the subject of the mediation without deliberation and approval for such action at an open session.