Sarah Cooper-Lesadd, who represents Pen-y-Bont Bro Morgannwg, announced her decision on Tuesday, September 15, after what she described as growing disagreements with Reform UK.
She said: “I cannot support Reform’s attacks on people seeking sanctuary or other vulnerable groups.
“I particularly reject the way minorities have too often been used as political targets.
“I do not believe anyone should be scapegoated or dehumanised to win votes, and I will not be part of a politics that does that.”
Ms Cooper-Lesadd said she joined the Senedd to be a “voice for care-experienced people” and to improve the lives of those who feel overlooked.
She said: “I stood for the Senedd to be a voice for care-experienced people, who are still badly under-represented in our politics.
“I want to improve people’s lives, stand up for people who are overlooked and get things done.
“My approach is evidence-led and rooted in what works for our communities.”
She criticised Reform UK for lacking interest in governing Wales and focusing more on division and headlines than solutions.
Marc Jones, Chair of the Plaid Cymru Senedd Group, said: “The Senedd Group and Plaid Cymru’s National Executive have today taken the decision to allow Sarah Cooper-Lesadd MS to join the party as our 44th Member of the Senedd.
“A decision to allow a member to cross the floor, particularly from Reform UK, is not taken lightly.
“This follows a period of reflection, discussion and a proper internal process in line with our party’s constitution.”
He said it had become clear Ms Cooper-Lesadd was” uncomfortable” with Reform UK’s values and rhetoric.
He said: “We are therefore pleased to welcome Sarah to Plaid Cymru and look forward to the contribution she can make to our party.”
