British Prime Minister Rishi Sunak is set to declare on Monday that only his Conservative Party can effectively challenge a Labour-led administration. He will also argue that casting a vote for Nigel Farage's right-wing Reform UK could undermine the Conservatives' ability to form a robust opposition. Sunak appears to be acknowledging the likelihood of defeat in Thursday's election and is appealing to right-leaning voters who might consider voting for Farage's party in protest against his Conservative government.

The Conservatives are expected to lose power after 14 tumultuous years, which included Britain's decision to exit the European Union in 2016 and the subsequent cost of living crisis triggered by the Covid-19 pandemic and Russia's invasion of Ukraine. Recent opinion polls have shown Keir Starmer's centre-left Labour Party leading by about 20 points, with Reform UK potentially dividing the centre-right vote and the centrist Liberal Democrats further eroding Conservative support.

At a rally, Sunak will assert that Reform UK lacks the capability to win enough seats to oppose Labour, noting the party's previous aspiration to secure a few parliamentary seats. He will illustrate the scenario of a Labour government being opposed by only a handful of Reform UK MPs, calling it a disastrous situation that could take decades to recover from. Farage, a highly recognizable and polarizing figure, has long been a critic of the establishment and the European Union, and has more recently supported Donald Trump in the United States.

Farage launched his campaign in early June, aiming to replace the Conservatives as the primary right-wing party. Polls suggest that Reform UK's support reached its peak in the latter half of June, shortly before Farage commented on the West's role in provoking Russia's invasion of Ukraine. Some of his candidates have been removed due to racist or inappropriate comments. Despite potentially receiving millions of votes, Reform UK is unlikely to secure more than a few parliamentary seats, which could nonetheless split the right-wing vote and benefit Labour.

Britain is poised to elect a centre-left government at a time when much of Europe is shifting to the right, including France where Marine Le Pen's far-right National Rally secured the first round of a parliamentary election on Sunday. With many voters still undecided, Sunak will make a final plea for support, promising that the Conservatives will advocate for voters and represent their values if Labour comes to power.