belfast senior member northern ireland democratic unionist party wednesday blame rival sinn fein collapse talk form power-sharing government suggest dup would compromise key issue irish language first public statement dup collapse talk member parliament gregory campbell accuse sinn fein hold back government narrow political agenda campbell suggest dup would accept sinn fein demand additional right fund irish language speakers key stick point talk recent weeks say already receive ample public fund party agreement elevate irish language others health education vital public service say dup blame sinn fein northern ireland talk collapse