Reform Wales leader Dan Thomas has stepped down from his position after being arrested on suspicion of assault and controlling or coercive behaviour, saying he did not want the police investigation to distract from the party’s work in the Welsh Parliament.
Thomas, 45, was arrested on Sunday, September 13, in the Aberbargoed area of Caerphilly, according to Gwent Police. The force said he was later released on bail while further inquiries are carried out.
In a statement issued by Reform UK, Thomas said he was leaving the leadership role for personal reasons and stressed that he had been released without charge.
“I stress that I have done nothing wrong, but I do not want the coming headlines to be a distraction from the fantastic work our Senedd team is doing in holding this government to account.”
Thomas did not take part in First Minister’s Questions earlier on Tuesday as the political fallout from his arrest emerged.
Explaining his decision to leave the leadership post, Thomas said his time at the helm had been a major achievement for Reform Wales, which he said had grown from having no elected members to becoming the largest opposition group in Welsh history.
“It has been the honour of my life to have been the leader of Reform Wales and see this party go from zero to 34 elected members and become the largest opposition group in Welsh history.
“With deep regret, I am now standing down from this position due to personal reasons.
“Over the weekend, I was reported to the police and was released without charge.”
Thomas also said he would remain in public office as a representative for Casnewydd Islwyn and would support the person chosen to replace him as Reform Wales leader.
“I will continue to serve my constituents in Casnewydd Islwyn and will fully back whoever the group selects as its next leader.”
Gwent Police confirmed that an arrest had taken place but did not identify the man by name.
“On Sunday 13 September a 45-year-old man, from the Aberbargoed area, was arrested on suspicion of assault and engaging in controlling/coercive behaviour.
“He has been bailed pending further enquiries.”
Thomas was appointed leader of Reform Wales by party leader Nigel Farage in February, placing him at the head of the party’s growing presence in the Welsh Parliament.
Before joining Reform UK, Thomas was a Conservative councillor and served as leader of Barnet Council from 2019 to 2022. He defected to Reform in June 2025.
He later resigned as a councillor for Finchley Church End after moving back to Wales with his family.
Thomas has previously spoken about his links to Wales, telling a conference earlier this year that he had been “born and raised” in the Valleys before moving to London to build a career in financial services.
His resignation now leaves Reform Wales preparing to select a new leader as Thomas steps away from the position while police inquiries into the allegations continue.