Sectarian solidarity v New Alliances

Sinn Fein has attacked the SDLP for opposing the new super councils and joining with all the other parties in Northern Ireland to seek changes in the present proposals. Is sectarian solidarity more important than fighting gerrymandering and sectarian headcounting? Or with such multi-party opposition to the proposals and the final decision given back to a devolved Assembly is Sinn Fein worried it will lose a vote so is engendering a sectarian bogeyman to push the SDLP back into line?