In December 2018 the UK and Welsh Governments announced that an independent review would be carried out into the Swansea Bay City Deal.
Ym mis Rhagfyr 2018, cyhoeddodd Llywodraethau Cymru a’r DU y byddai adolygiad annibynnol yn cael ei gynnal i Fargen Ddinesig Bae Abertawe.