Is Plaid Cyrmu’s success more than a flash in the pan?

Guy Griffiths, Client Executive
05/06/2026

Wales has not traditionally been a politically volatile nation. Labour’s 100 years of electoral success was the longest winning streak of any political party in the world. Since 1922, Labour had won more seats and votes in Wales than its rivals in every general election and at all six Senedd elections. That century-long run ended on 7th May. In this uncharted political territory, one party has emerged as the new pace setter: Plaid Cymru.

While Plaid won 43 seats in the Senedd and 35.4% of the national vote share, it crucially fell short of an overall majority. Labour’s collapse left Plaid in a two-horse race with Reform UK, with the parties securing 77 of the 96 seats between them. While Reform weaponised macro-political concerns on immigration and net zero to sweep through industrial and working-class areas, Plaid ran on a ticket of a civic renewal and a refreshed belief that a new progressive style of politics can stand up to the rising tide of populism across the UK. Their success came from building on a strong support base in Welsh-speaking part of Wales, adding many traditional Labour supporters and successfully positioning themselves as the main left-of-centre alternative to Reform.

However, this hastily assembled support base could quickly crumble. The first major hurdle for the nationalists is cementing their position as the undisputed voice of the left in Wales. For decades, Welsh Labour successfully branded itself as the radical, protective shield of working people against a hostile Westminster. Now that that image has fractured, Plaid must prove that its version of progressive democratic socialism is a viable reality rather than a mere protest movement. This requires sustaining support beyond their traditional heartlands into urban, post-industrial hubs in the South and along the coast. If they fail to convince voters that they can deliver tangible improvements in areas such as health and education, their popularity could well evaporate at the next election.

However, the biggest issue for new First Minister Rhun ap Iorwerth is the elephant in the room: the question of independence. Total independence remains an aspiration for a minority of the Welsh electorate. Plaid must now simultaneously maintain support among their nationalist base, while reassuring anxious moderates that their immediate focus is strictly on making the most of devolution. Move too close to independence and the coalition collapses; pivot too far from their heartlands and the party loses its distinct political identity.

From Plaid’s first weeks in government, this delicate balancing act seems to be at the heart of their strategy. In his Statement of Priorities in the Senedd on 19th May, ap Iorweth said that he wanted to “make early progress on the devolution of justice and policing, the Crown Estate, and developing a fair funding formula, including matters such as rail, to tackle the injustice of HS2—all issues that have majority support in this Chamber”.

Pushing for greater devolved powers in policy areas that align with Plaid’s promise of civic renewal, revitalised government and improved public services may not hit the headlines or register with voters on either side of the independence debate, but it will allow Plaid to build their experience in government and improve their chances of winning a mandate for an independence referendum at the next Senedd election in 2031.

Plaid’s historic breakthrough has completely shattered the predictable rhythms of Welsh politics. Their task now is to translate electoral success into a unifying and competent national government. Whether they can achieve this and fend off the populist challenge from Reform UK, whilst stopping a future Labour revival, depends on Plaid’s ability to turn from a historical tradition of protest into a party that can deliver real results in government.