Sarah Cooper-Lesadd - Member of the Senedd for Pen-y-bont Bro Morgannwg | Reform Watch

Profile and accountability tracker for Sarah Cooper-Lesadd, Member of the Senedd for Pen-y-bont Bro Morgannwg. Plaid Cymru.

Role: Member of the Senedd for Pen-y-bont Bro Morgannwg

Party: Plaid Cymru

Member of the Senedd for Pen-y-bont Bro Morgannwg, covering Bridgend and the Vale of Glamorgan, elected in May 2026. She was elected as a Reform UK member and served as the party's shadow minister for children, young people and skills, and chairs the Senedd's Legislation Committee. On 15 September 2026 she left Reform UK and joined Plaid Cymru and its Senedd group. She grew up in the care system and has said she entered politics to represent care-experienced people. She retains her seat, so no by-election arises, and no announcement has been made about her committee chairmanship.

Recorded incidents (showing 1-1 of 1)

Sarah Cooper-Lesadd defected from Reform UK to Plaid Cymru after alleged threat of expulsion

Category: ethics violation

Sarah Cooper-Lesadd left Reform UK to join Plaid Cymru and will sit as a Plaid Cymru Member of the Senedd for Pen-y-bont Bro Morgannwg. Reform UK’s director of external affairs Matthew MacKinnon said she was on the verge of being expelled from the party and called for her to resign her Senedd seat, criticising her conduct during the selection and election process. Cooper-Lesadd said she did not dispute that she had been facing ejection but rejected claims she had manipulated assessors, arguing the selection process emphasised media skills and that her priorities included cross-party work on rights for care leavers. The defection occurred amid wider turmoil in Reform UK Wales, with several candidates quitting or being removed from lists amid concerns over online behaviour, and the party’s Welsh leader Dan Thomas arrested on suspicion of assault and controlling or coercive behaviour; Thomas denies wrongdoing.