The Department for Business, Energy and Industrial Strategy (BEIS) is responsible, with the Office for National Statistics (ONS) for publishing the National Statistics on trade union membership.
Yr Adran Busnes, Ynni a Strategaeth Ddiwydiannol sy’n gyfrifol (ynghyd â’r Swyddfa Ystadegau Gwladol) am gyhoeddi’r Ystadegau Gwladol ar aelodaeth o undeb llafur.