A by-election will take place in Caerphilly next month to fill the vacant Senedd seat left by the sudden death of Labour politician Hefin David.
A by-election happens when a seat becomes vacant between general elections, giving local voters the chance to choose a new representative.
The Welsh Parliament has confirmed that the vote will be held on Thursday 23 October 2025. Mr David, who had served as the Member of the Senedd for Caerphilly since 2016, died suddenly on 12 August at the age of 47.

Labour has held the Caerphilly seat since the Senedd, then known as the National Assembly for Wales, was first established in 1999. At the last Senedd election in 2021, Labour secured half of the 60 seats. This meant it already needed the support of at least one opposition member to pass laws and budgets. Losing Caerphilly could make that job even harder, particularly as parties look ahead to the 2026 election.
Plaid Cymru was the first party to announce a candidate, choosing former council leader Lindsay Whittle. Labour has selected Richard Tunnicliffe, while the Conservatives are putting forward Gareth Potter. Llŷr Powell will stand for Reform.
Key dates for voters include the deadline to register, which is midnight on Tuesday 7 October. Postal votes will be sent out from 6 October, with applications closing the following day. The deadline for proxy vote applications is 15 October. Polling stations will open from 7am until 10pm on 23 October, with counting beginning later that night.
To vote in this election, you must be registered, aged 16 or over on polling day, and live in the Caerphilly constituency. Registration can be completed online at Register to vote. Anyone unsure about their status is advised to contact Caerphilly Electoral Services at Bargoed House, 1 St Gwladys Way, Bargoed, by emailing [email protected], or calling 01443 866586.
