Welsh politics has been thrown into a new era following Plaid Cymru’s historic victory in the Caerphilly by-election, a result that has not only rattled the long-standing Labour dominance in the region but also raised urgent questions about Plaid’s vision for the country’s future—especially its stance on the environment. As the Senedd elections loom on the horizon for May 2026, the party’s environmental agenda, or perceived lack thereof, is coming under increasing scrutiny from both supporters and critics alike.
The Caerphilly by-election, held on October 24, 2025, was sparked by the death of Labour politician Hefin Wyn David. In a stunning upset, Plaid Cymru’s Lindsay Whittle clinched the seat with 47.38% of the vote, a swing of nearly 27% from Labour, who had held this former mining town for over a century. Reform UK’s Llŷr Powell finished second with 35.9%, while Labour’s Richard Tunnicliffe trailed in third with just 11%. According to Nation.Cymru, this was the first time Labour has lost Caerphilly since the Senedd’s creation, and the first Senedd by-election to break the 50% turnout barrier.
The result has been hailed as a bellwether for next year’s Senedd elections, with Plaid Cymru positioning itself as the leading alternative to Labour and the only viable bulwark against the rising Reform UK. Plaid leader Rhun ap Iorwerth declared, “This result shows that Plaid is no longer just an alternative. We are now the real choice for Wales, the only party able to stop billionaire-backed Reform and offering a better future that works for everyone.” Lindsay Whittle echoed this optimism, stating, “Tonight’s result shows what’s possible when people come together to back practical solutions and protect what matters most. We’ve beaten billionaire-backed Reform and, with the same determination, we can do it again in May 2026. Caerphilly has shown the way—now Wales must follow.”
Yet, while Plaid Cymru celebrates its political momentum, an opinion piece published on October 25, 2025, by Eben Myrddin Muse in Nation.Cymru raises a critical concern: What is Plaid’s actual plan for Wales’s environment? Muse, who attended the party’s recent conference at Swansea’s Brangwyn Hall, observed that nature and environmental protection were conspicuously absent from the main agenda. “Nature was left off the agenda: for the vast majority of the conference, its protection, its future, its significance, was either utterly absent, or relegated to self-congratulatory back-patting remarks at fringe events dedicated to other things,” Muse wrote.
This omission is particularly striking given that Plaid Cymru was instrumental in pushing the Senedd to declare a nature crisis back in 2021. However, the current attitude, as described by Muse, seems to treat nature protection as a bureaucratic nuisance, especially to industry lobbyists who see regulations as obstacles. “Declarations are cheap, but for nature, regulations matter,” Muse noted, underscoring the importance of concrete policy over symbolic gestures.
At the conference, Deputy Leader Delyth Jewell stood out as a rare champion for nature, participating in a WWF-sponsored panel and advocating for environmental benefits in farming subsidies. “It’s public money!” she asserted, emphasizing the need for accountability in how farming incentives are distributed. Yet, Jewell’s voice appeared lonely amid a wider party discourse that, according to Muse, seemed more interested in appeasing industry lobbyists than championing environmental stewardship.
Party leader Rhun ap Iorwerth’s 45-minute keynote speech failed to mention nature at all, a silence that did not go unnoticed. Meanwhile, lobbyists at the event pressed Llŷr Gruffydd, the presumptive farming minister, to “review” and “explore practical and innovative solutions”—in other words, to potentially dismantle regulations designed to protect Wales’s rivers from agricultural runoff, which is a major source of pollution. Muse argued that this process of “declawing” regulation has already undermined the Sustainable Farming Scheme and could threaten the Environmental Governance Bill as well.
Wales is facing a dire environmental crisis, with one in six species at risk of extinction and rivers in poor health. Yet, Plaid Cymru has not formally endorsed the global 30x30 target—a commitment to protect at least 30% of land and waters by 2030—despite Llŷr Gruffydd acknowledging that such goals are “central to efforts to halt and reverse the loss of nature by 2030.” Without a clear and actionable plan, Muse warns, Plaid risks inheriting responsibility for ongoing biodiversity loss if it forms the next government.
The environmental debate is further complicated by the challenges facing Welsh farming. The sector is already in decline, with an aging workforce, falling product values, and the added pressures of Brexit. Current incentives, Muse contends, risk driving both Welsh nature and farming “to the same oblivion,” with negative repercussions for rural communities and the Welsh language. The influence of reactionary lobbyists, who allegedly have Plaid Cymru’s ear, threatens to push policies that benefit polluters at the expense of both farmers and the environment.
Public sentiment in Wales, however, appears firmly on the side of environmental protection. There is widespread support for clean rivers, for tying public funding to environmental benefits, and for reintroducing species such as beavers. The Green Party, buoyed by a surge in membership, is poised to challenge Plaid Cymru in urban and student-heavy constituencies in 2026, while the Liberal Democrats are making clean water their signature cause. As Muse observed, “For the many for whom the environment is their principal motivator, they may find the Lib Dem promise to clean things up to be more compelling, more credible.”
All of this sets the stage for a complex political battle. Rhun ap Iorwerth has spoken passionately about governing for both rural and urban Wales, but the party’s dual constituency—urban progressives and rural conservatives—faces a potential collision over environmental policy. Muse concluded, “Plaid Cymru has no God-given right to the votes of people who care about nature. To deserve them, they must reject the idea that to look out for farmers is to gut regulation and ignore Wales’ environment, because that is a lie. It is possible to champion both nature and Wales’ farmers. In fact, it’s the only way forward that makes any sense.”
With the next Senedd elections fast approaching, Plaid Cymru stands at a crossroads. Its recent electoral triumph in Caerphilly has opened the door to government, but its environmental blind spot could prove costly unless the party finds the courage—and the policies—to champion both nature and the people who depend on it.
