The SDLP, Alliance and Sinn Fein have condemned the decision by loyalists to resume pickets outside the Catholic church in Harryville, Ballymena, at the weekend if Orangemen are not allowed to march down Garvaghy Road, Portadown, on Sunday.
Details have emerged that loyalists, who called off their protests in May after Apprentice Boys were allowed to march through Dunloy, are planning to picket Masses at Our Lady's Church in Harryville until the Parades Commission's decision to reroute the Drumcree Orange march is reversed.
The "Spirit of Drumcree" spokesman, Mr Joel Patton, said he learned of the decision to hold protests at an emergency meeting on Tuesday night.
The SDLP North Antrim Assembly representative, Mr Sean Farren, urged all politicians with influence over the protesters to persuade them to abandon it. Mr Farren's North Antrim colleague, Mr James McCarry, of Sinn Fein, said the decision to picket Harryville church was "a blatant act of sectarian discrimination designed to pressurise not just the Mass-goers but the Garvaghy Road residents and, indeed, the whole nationalist population".
The Alliance Assembly member for South Antrim, Mr David Ford, said: "There was never any justification for linking worship at the chapel at Harryville with Orange marching at Dunloy. To link worship at Harryville with marching at Drumcree is even more inexcusable."