One can no longer say, with absolute certainty, that the UK maintains a strong two-party system. The Conservative-Labour dominance that has been a staple feature of post-war British politics has never looked weaker. In recent years, we have seen the fragmentation of the two-party system as people have become increasingly apathetic and disillusioned towards the two mainstream parties. Smaller, less established parties have moved to the forefront of British politics. This rejection of the status quo was further reinforced by the Gorton and Denton by-election result last week.
The Green Party, which has gained significant momentum since Zack Polanski became leader, won the by-election with more than 40% of the vote. Hannah Spencer garnered 14,980 votes, Reform UK’s Matt Goodwin came second with 10,578, while Labour’s Angeliki Stogia was third with 9,364. This win by the Greens is extremely significant and historic because the seat had been held by Labour for nearly 100 years, making it one of Labour’s safest seats. In the 2024 General Election, Labour took the Greater Manchester seat with more than 50% of the vote. By winning the seat with 40% of the vote, Hannah Spencer overturned a massive 13,000-vote Labour majority. It is the first time that candidates from two parties other than Labour and the Conservatives have taken both first and second place in a Westminster by-election in England.
Safe seats have long helped entrench the two-party system. The UK’s winner-takes-all, first-past-the-post electoral system means that larger, more well-established parties are rewarded as they have more concentrated support. With their support concentrated, they can secure seats with only a plurality of the vote. Smaller parties tend to have dispersed support spread too thinly across constituencies to translate into strong parliamentary representation. It is because of this that only Labour and the Conservatives have consistently been able to form governments. The Gorton and Denton result, however, suggests that this order is dwindling.
The Green Party overturning a safe seat in such dramatic fashion signals great dissatisfaction with the Labour Party and suggests that Britain’s move toward a more fragmented, multiparty political landscape can no longer be dismissed or ignored.
The signs of these seismic shifts were evident in the 2024 election results. While the Labour Party won an extremely significant majority, they only obtained 34% of the national vote share, meaning that roughly two-thirds of voters opted for other parties. This was one of the lowest vote shares for a majority government in British history. It was also the most disproportionate election ever. The result, therefore, highlighted that even though large, established parties enjoy a structural advantage under the electoral system, they are not as dominant as they once were. Their ability to govern was down to the mechanics of the electoral system rather than securing majority support from the electorate. While Labour achieved decisive institutional power, the relatively low vote share signalled a weaker voter base and a more divided and volatile political landscape. The by-election confirmed this message, as it showed that two of the key foundations of Labour’s traditional electoral coalition have crumbled.
Angela Rayner, the former deputy leader of the Labour Party, said the result was a “wake-up call” that illustrated the party needed to be “braver”. She seemed to voice that Labour needs to move more to the left. Arguably, the Labour Party has lost itself in its attempts to neutralise the threat of Reform UK. Reform UK continues to lead the polls with a policy platform focused on immigration. Labour’s attempts to counter Reform UK have involved adopting elements of its opponent’s agenda and rhetoric. When the Labour government announced its immigration proposals, around 40 Labour MPs raised concerns about the impact they would have on migrants already living here, describing the retrospective approach as “un-British” and “moving the goalposts”.
Labour’s approach, therefore, has contributed to shifting the Overton window, normalising ideas that were once considered fringe and creating political space for Reform UK’s platform. This has left many long-time Labour voters feeling disconnected from the party. The by-election confirmed this as the result shows that the Greens, who position themselves as the progressive left, can mobilise ethnic minorities and more left-wing Labour voters who feel politically homeless in Starmer’s Labour. Ultimately, Labour’s core voter base has been on the decline, but this recent result only reaffirmed this.
Exclusive polling following the election shows the Green Party have leapfrogged Labour in voting intention polls, as the second most popular UK party. The Greens, like Reform, are emerging as a serious, seat-winning electoral force. The old left and right no longer define politics – cultural issues are now a key factor. This further reinforces the UK’s shift towards a multiparty system. In a letter to his MPs, the Prime Minister said that the Green Party was no longer made up of “harmless environmentalists”. He recognises the electoral threat Labour now faces from both sides of the political spectrum. Despite this loss of a party stronghold and calls for him to resign, the Prime Minister pledged to“keep on fighting”.
The Conservatives are faring even worse than the Labour Party, as they are struggling to maintain support. With several high-profile defections to Reform UK, it appears that the traditional political order, long defined by the Conservatives as the dominant right-wing party, is clearly eroding. There is still time for both parties to regroup before the next general election, but current trends suggest they cannot solely rely on their traditional bases. The threat of the minor parties is very real. Ultimately, the Gorton and Denton by-election is an urgent signal of the need to prepare UK democracy for a multi-party future. Many agree that a new electoral system is needed to reflect this new political reality.