Analysis: Caerphilly By-Election Result Shows How Nigel Farage Could Be Reform's Achilles Heel

Nigel Farage hasn’t had much to feel unhappy about of late.

With Reform UK riding high in the polls, his supporters and even the man himself are allowing themselves to dream about the prospect of him becoming prime minister.

But Plaid Cymru’s historic victory in the Caerphilly by-election is an important reality check for Farage and his party.

They were supremely confident that their man, Llyr Powell, would be the one to end more than a century of Labour dominance in the seat.

Opinion polls showed them running neck-and-neck with Plaid’s Lindsay Whittle as Reform – who received just 459 votes the last time the seat was up for grabs – made good on Farage’s pledge to “throw everything” at winning it.

In the end, however, the Welsh nationalists won a relatively comfortable 3,848 majority on a highly impressive 47% of the vote, compared to Reform’s 36%.

Labour, who won the seat with a 5,000 majority four years ago, received just 11% of the vote.

The suggests that in the privacy of the polling booth, a large number of left-of-centre Caerphilly voters opted to lend their votes to Plaid Cymru as a way of keeping Reform – and Farage – out.

Polling expert Luke Tryl, of the More in Common think-tank, posted on X: “Scale of Plaid win in Caerphilly is significant, not least because of what it says about the potential for progressive tactical voting in (relatively) high turnout elections to block Reform. Voters in this race knew it was a Plaid-Reform contest and voted accordingly.”

Tryl said that could also be a huge factor in next May’s elections for the Welsh Senedd, Scottish Parliament and in council seats across England.

“Whereas Labour were the party that was squeezed here, in contests where they are the main contender against Reform can they, even as incumbents, get disillusioned progressives to come back and back them tactically?

“For Reform, this places a greater premium on growing their support pool and reaching more ‘soft Reform’ voters.

“Turning out a highly-motivated base clearly works in fragmented local council elections but isn’t alone enough in the face of tactical voting.”

Farage is the very definition of a Marmite politicians – adored by his supporters but despised by his opponents.

The prospect of him walking through the doors of No.10 will be enough of a motivation for millions of voters on the left to back whichever party in their constituency is best placed to stop Reform.

Plaid Cymru’s victory in Caerphilly could well be a taste of what’s to come for Farage as he faces the already-daunting task of trying to take Reform from just five MPs to government at the next election.