The Commission has determined that a county constituency be created from:The Blaenau Gwent and Rhymney UK Parliamentary constituency,and:The Caerphilly UK Parliamentary constituency.
Mae’r Comisiwn wedi penderfynu creu etholaeth sirol o’r canlynol:Etholaeth Seneddol y Deyrnas Unedig Blaenau Gwent a Rhymni,ac:Etholaeth Seneddol y Deyrnas Unedig Caerffili.