Plaid Cymru surges ahead of Reform UK with Labour in fourth place in latest ITV Senedd election poll

• ITV Wales' Political Editor Adrian Masters reports.

Plaid Cymru has surged ahead of Reform UK as the predicted largest party in the upcoming Senedd election, according to the first poll of 2026 from ITV Cymru Wales.

Rhun ap Iorwerth's party increased its vote share from 30% to 37% since our last poll in September 2025, with Reform UK dropping from 29% to 23%.

For the first time ever, the Green Party is polling in third place at 13%, with Labour in fourth - its lowest ever point -at 10% alongside the Conservatives.

The latest figures from the poll carried out by YouGov for ITV Cymru Wales and Cardiff University come less than four months before people in Wales go to the ballot box on 7 May, 2026, to elect 96 Senedd Members - an increase from the current 60.

Senedd 2026 seat projection

This is the first Senedd election with a new voting system and modelling predicts that the vote shares in this poll would translate to Plaid Cymru winning 45 seats, just four short of an overall majority.

That is well ahead of any other party, with Reform UK on 23, the Greens on 11, Labour on eight and the Conservatives on six.

Dr Jac Larner, from Cardiff University's Welsh Governance Centre, said: "This poll shows a stark contrast to previous polling, with a substantial 14-point gap between Plaid Cymru and Reform UK in Senedd voting intention—a significant shift from when the two parties appeared neck and neck.

"While any single poll should come with a health warning and this may be something of an outlier, it continues broader trends we're seeing in Welsh polling, where Plaid Cymru have enjoyed a modest boost, and trends in England, where Reform support appears to be plateauing while the Greens have surged.

"Two patterns are particularly noteworthy. First, the gains for both the Greens and Plaid Cymru appear to be drawing from voters who were previously undecided, rather than coming from other parties.

"Second, Plaid Cymru seem to be consolidating their position as the party best placed to challenge Reform UK —57% of respondents in our sample identified them as such."

Party reaction

Plaid Cymru say the poll confirms the election is a two-horse race between them and Reform, and claim Labour is "finished" after decades in charge.

A party spokesperson said: “More and more people are realising they face a choice between two very different futures, and are choosing to back Plaid Cymru’s positive vision for Wales.

“That’s because we are the only party that will always stand up for Wales, with new leadership and serious plans to fix our NHS and help people with the cost-of-living crisis. Reform is focused on chasing headlines and getting Nigel Farage closer to Number 10 - not on Wales’ future."

As for Welsh Labour, a party source told ITV: "Welsh Labour isn't taking voters for granted and we know there's work to do. Just this morning we heard Plaid pivoting back to their plan for independence, but still not saying how they will pay for the promises they're making. Welsh Labour is focusing on helping making people's lives better from making transport more affordable to bringing down waiting lists."

Plaid Cymru has also overtaken Reform when it comes to which party people in Wales would vote for in the next UK General Election.

This is reflected in figures showing more people now think Plaid leader Rhun ap Iorwerth is doing a good job as leader, while more people now think Nigel Farage is doing a bad job as leader of Reform UK compared to our previous poll.

Westminster voting intention for people in Wales (YouGov MRP Model):

• Plaid 29 (+6)

• Reform 25 (-4)

• Lab 13 (-5)

• Con 12 (+1)

• Green 12 (+5)

• Lib Dem 6 (-3)

• Other 2 (-2)

Analysis from ITV Cymru Wales' Political Editor Adrian Masters

Today is the day that people living in Cwm Gwaun in Pembrokeshire celebrate Hen Galan, the “old New Year".

For political parties here in Wales, our poll marks the first day of a new year which looks a lot like the old year but with a number of twists and even more jeopardy.

So while the main headlines from the first poll of 2026 remain the same as those in 2025, there are some significant changes. Plaid Cymru’s extended lead, Reform UK’s slight falter but continued second place and the Greens’ new third-place showing all demonstrate that change is in the air, but what form it takes is far from certain.

If the vote shares reflected in this poll were to become reality in May, it is now highly likely that the Senedd will see the biggest political upheaval since it came into being as the Welsh Assembly back in 1999.

It could mean Labour losing power for the first time in those 27 years, and the likelihood of a non-Labour First Minister is higher than ever.

As things stand, and with political tensions between the parties as they are, that looks most likely to be Rhun ap Iorwerth, leading a Plaid Cymru government which may or may not be able to survive without reaching a deal with Labour.

Eluned Morgan’s party may not be in a position to do such a deal, anyway. Based on these figures, Labour and the Conservatives could both well be in states of devastation, literally and emotionally, which will take them some years to get over.

While Reform UK’s opponents may be gleeful to see its figures falter a little, the party will not abandon its hope that it can still become the largest party here in Wales after May, nor will its efforts let up.

Even if it fails in that ambition, forming the official opposition in the Senedd would be a remarkable achievement for a party that only won 1.6% of the vote in 2021.

With the Greens now eyeing up an increasing number of seats, the Senedd of 2026 will be very different. Welsh politics will be very different, too.

• YouGov’s total sample size for the Senedd Voting Intentions MPR Model was 1,220 adults (16+). Fieldwork was undertaken between January 5th-12th, 2026.

• YouGov’s total sample size for the Westminster Voting Intentions MPR Model was 1,205 adults (+18). Fieldwork was undertaken between January 5th-12th, 2026.

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