The Ulster Unionist party has threatened to break off all contact with SDLP councillors after the UUP Lord Mayor of Derry, Mr Richard Dallas, was stripped of many mayoral privileges.
SDLP and Sinn Fein members of Derry City Council joined forces against Mr Dallas after he took part in an Orange, blockade of Craigavon bridge in the city during the Drumcree crisis last month.
A UUP councillor in Belfast, Mr Jim Rodgers, said: "The Unionist hierarchy are incensed over what happened to Mr Dallas. We may well have to break off all contacts with them [the SDLP] until Cllr Dallas's powers are restored."