Reform is likely to appoint Helen Jenner to take over from Dan Thomas as the party’s Welsh leader, sources have told BBC Wales.
It is understood she is the favourite to replace Thomas, who quit following an arrest on suspicion of assault, and that “very senior” Reform figures had backed her.
Jenner, an MS for Bangor Conwy Môn, is the party’s interim Welsh leader and was Thomas’ deputy.
Thomas stood down after he was arrested and bailed by police at the weekend on suspicion of assault and controlling coercive behaviour.
He says he has done nothing wrong.
Meanwhile, chief whip Llŷr Powell told BBC Wales that he has ruled himself out of standing for the leadership.
Thomas has not been suspended and continues to represent Reform in the Senedd as MS for Casnewydd Islwyn.
Jenner is yet to speak publicly about her intentions.
The party’s health spokesperson James Evans claimed on Wednesday he had majority support in the group but decided not to stand after speaking to his family.
If there is more than one candidate it is expected there will be a secret ballot of Reform MSs – but no vote of the membership.
Thomas was appointed by Nigel Farage in February.
Helen Jenner is a former English teacher who was born in the south Wales town of Neath and grew up on Anglesey.
In a BBC Walescast podcast episode during the summer Jenner, a Welsh speaker, said that people online had told her she had “no right” to attend the National Eisteddfod, because of her membership of Reform.
Jenner stood for the Brexit Party at the 2019 UK general election, and was previously a member of UKIP, when it was led by current Reform UK leader Nigel Farage.
On Walescast she said Farage had helped her become engaged in politics.
“It was seeing him, and then watching his YouTube clips in the European Parliament and everything: I’ve never seen anybody so animated
“I felt he was really principled and I suddenly thought ‘oh, I actually care about politics now’.”
Additional reporting by Mark Palmer
