Reform UK’s Welsh leader Dan Thomas denies wrongdoing as he stands down following arrest

Dan Thomas has insisted he did nothing wrong and said he stepped down to avoid being a distraction after being arrested on suspicion of assault and coercive behaviour.

By Steve Rowland · AI-assisted production, human-approved (how we work)
Published 16 September 2026 at 01:05 · Updated 16 September 2026 at 04:57

Developing · updated 21 hours ago

We are still following this story and this page updates as more is confirmed.

In brief

What happened

Reform UK’s Welsh leader Dan Thomas has resigned from his leadership post after being arrested on suspicion of assault and controlling or coercive behaviour. Gwent Police confirmed a 45-year-old man was arrested on 13 September and has since been released on bail pending further enquiries. Thomas stated he is stepping down due to "personal reasons" but intends to remain as a backbench Member of the Senedd for Casnewydd Islwyn.

Why it matters

Thomas had led Reform Wales as it grew to 34 elected members, making it the largest opposition group in Welsh history after the May elections. His departure coincided with further disruption for the party, as Reform MS Sarah Cooper-Lesadd defected to Plaid Cymru on the same day. Opposing political figures from Welsh Labour, the Conservatives, and the Liberal Democrats also criticised Reform following the news.

What's next

Reform MS Llyr Powell confirmed that a formal process will take place to select a new leader, who is expected to be chosen by the end of the month. Thomas stated that he will fully support the incoming leader while continuing to represent his constituents. Meanwhile, Gwent Police's investigation remains ongoing while Thomas stays on bail.

Reform UK’s Welsh leader Dan Thomas has denied any wrongdoing after being arrested on suspicion of assault and controlling or coercive behaviour, saying he is stepping down to avoid becoming a "distraction".

In a statement released on Tuesday afternoon, the Member of the Senedd for Casnewydd Islwyn said: "Over the weekend, I was reported to the police and was 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."

Gwent Police confirmed that a 45-year-old man from the Aberbargoed area in Caerphilly was arrested on Sunday 13 September on suspicion of assault and engaging in controlling or coercive behaviour. The force stated that he has since been released on bail pending further enquiries.

Thomas was absent from First Minister’s Questions and the opening plenary session of the new Senedd term on Tuesday, with Reform initially stating he was absent for "personal reasons". Thomas has confirmed he intends to stay on as a backbench MS representing his constituency.

The resignation comes alongside wider disruption for Reform in Cardiff Bay, breaking on the exact same day that Reform MS Sarah Cooper-Lesadd defected to Plaid Cymru. There have also been persistent reports of infighting within the group since May.

Thomas was personally appointed to head the Welsh party by Nigel Farage in February, with the leadership opting for an outsider partly to create distance from former Welsh leader Nathan Gill, who was jailed for accepting bribes to make pro-Russia statements in the European Parliament. In May's Senedd elections, Reform climbed from two seats to 34, finishing second behind Plaid Cymru and establishing Thomas as leader of the opposition.

Raised in Blackwood in the south Wales valleys, Thomas spent years in London financial services and local government, leading Barnet Council from 2019 to 2022. After standing unsuccessfully as a Conservative candidate in Islwyn in the 2010 and 2017 general elections, he defected to Reform in June 2025 and moved back to south Wales.

Opposing politicians were quick to criticise Reform. Welsh Labour leader Ken Skates told the Press Association that "many questions will need to be answered", describing the situation as "quite incredible news" that demonstrated "appalling judgement" by Nigel Farage. Conservative Shadow Welsh Secretary Mims Davies and Welsh Liberal Democrat leader Jane Dodds also released statements criticising Reform's record and direction.

As for what happens next inside the party, Reform MS Llyr Powell told the Senedd Sources podcast that there will be a "formal process in which the group decides who is now going to lead it", with a new leader expected to be in place by the end of the month.

Gwent Police's enquiries remain ongoing while Thomas is on bail. I’ll be following the investigation closely — check back for updates.