The trade union Unite is to urge its members in the public service to reject the proposed new Haddington Road agreement in a forthcoming ballot.
Unite regional secretary Jimmy Kelly said workers would not be deceived by the new Haddington Road label being placed on the old Croke Park bottle.
Unite members rejected the Croke Park II proposals last month.
Unite will be the second union to recommend rejection of the Haddington Road proposals.
The Civil Public and Services Union has also urged members to vote against the proposed new agreement in a ballot.
Two teaching unions, TUI and ASTI, have effectively rejected the proposals but are not putting them out to a ballot of members.