What is the Senedd by-election in Caerphilly and who can vote?
The by-election is held on 23 October
- Published
On 23 October voters in Caerphilly will decide who will be their Member of the Senedd (MS) for the next six months.
It's an election that no one wanted, triggered by the sudden death of the constituency's Cardiff Bay politician.
It will fill a vacancy until May 2026 when another election will decide the make-up of the newly expanded Welsh Parliament.
This month's by-election has huge implications, with Labour facing a harder task running Wales should it lose.
All of the main parties are fielding candidates in the election - it is a key test for them as they prepare for the major event next year.
Why is the Caerphilly by-election happening and who will be able to vote?
Behind the by-election was the sudden death of the area's Member of the Senedd, Labour's Hefin David in August.
David was first elected in 2016, and Labour had held the seat since devolution began in Wales in 1999.
Although there is another election in May, the vacancy has to be filled in the meantime.
People aged 16 and above who are British, Irish or EU citizens who live in the constituency and are registered to vote will be able to take part.
Registered citizens of other countries who are otherwise able to live legally in the UK, the Isle of Man or the Channel Islands can also vote.
Unlike Westminster elections, ID is not required at a polling station.
You can check if you live in the constituency on the ONS election maps, external website.
What's at stake?
Before Hefin David's death, Labour held 30 of the Senedd's 60 seats.
That meant it was already relying on the help of at least one other opposition member when it needed to pass legislation, or its spending plans.
Liberal Democrat Jane Dodds helped Labour out at the last budget in return for a deal, including a ban on greyhound racing.
If Labour wins the situation will remain the same - if it loses it will need two opposition members, rather than just one, to win Senedd votes.
If that is not possible Labour could find itself unable to pass a budget, which would lead to significant automatic cuts if it was not resolved.
Labour has latched on to the situation to warn of cuts if voters turn against them - and been accused of "scaremongering".
However Mark Drakeford had, before Hefin David's death, vowed not to make significant changes to the pre-election budget in an attempt to make it politically neutral.
Caerphilly is also part of an important symbol for Labour - it's in their valleys backyard.
Losing would be a significant blow to the party, which has dominated politics in this part of south Wales since the early 20th century.
Opinion polls have suggested that Labour, Plaid Cymru and Reform are vying for the top spot for the next Senedd election.
What are other parties saying?
The election is the first real chance Reform UK has had to win a parliamentary seat in Wales, given its position in the opinion polls, and smaller Welsh council by-election successes.
The party has promised to throw "everything" the party has at the campaign and says it offers a "chance at genuine change".
Plaid Cymru has previously commanded thousands of votes in the constituency, although its never won it. It will be hoping to consolidate and go further, and wants to attract left wing voters opposed to Reform.
Plaid has said that a vote for Labour is a vote for Farage's party, portraying the election as a fight between them and Reform.
They are not the only three parties standing - the Tories say offer credible change, while the Welsh Liberal Democrats are focusing their campaign on the theme of care.
Meanwhile the Greens promised to put "people and the planet first". Candidates from Gwlad and UKIP are also standing.
Who are the candidates in the Caerphilly by-election?
The full list of nominees are:
Liberal Democrats: Steve Aicheler
Gwlad: Anthony Cook
Greens: Gareth Hughes
Conservatives: Gareth Potter
Reform: Llyr Powell
UKIP: Roger Quilliam
Labour: Richard Tunnicliffe
Plaid Cymru: Lindsay Whittle
You can find out more about the candidates here.
How will the constituency change after May 2026?
Caerphilly will cease to exist as a standalone constituency from May.
All Welsh Senedd constituencies are changing - with a map of 16 being used from that time.
Each constituency will elect six MSs, using a new list-based voting system which you can find out more about here.
The idea is that it is more proportional than the system that came before.
Next May Caerphilly will become part of the larger Blaenau Gwent Caerffili Rhymni constituency, which will stretch to the heads of the valleys in the north.
October's by-election will be fought through first-past-the-post, though, where the winner just needs to get more votes than each of the other candidates.
How can you vote in the Senedd by-election in Caerphilly?
Voting in the by-election will be like any other Westminster or Senedd first past the post election.
Polling stations will be open on 23 October from 0700 BST to 2200.
The deadline to apply for a proxy vote is 1700 BST on the 15 October.
The count will take place overnight and there will be coverage of the result on BBC TV, Radio and online.
BBC Wales is holding a live debate for the candidates of the Caerphilly by-election on 15 October. Click here to apply to be in the audience.