In doing so councils must have regard to the ten-year programme of electoral reviews published by the Commission and any directions issued to it by the Welsh Ministers.
Wrth wneud hynny, rhaid i gynghorau roi sylw i’r rhaglen deng mlynedd o adolygiadau etholiadol a gyhoeddwyd gan y Comisiwn ac unrhyw gyfarwyddiadau a roddwyd gan Weinidogion Cymru.