The British left is bigger than it thinks

The British left has been on a roller coaster journey in the past decade. From the first coming of Corbynism to its defeat at the polls, to the Green surge and the second coming of Corbynism, intermeshed with a post-Covid strike wave and anti-war movements calling for peace in Palestine and around the world.

In 2026, however, the radical left is squeezed between a Burnham bounce and the populist right, all making inroads among young and working-class voters. Is the radical left a busted flush? This article asks a simple question – how big is the left in Britain? Or, what base are we building on?

One of Jeremy Corbyn's great contributions was to show in 2015 the size of the British left, defined broadly enough to be inclusive and narrowly enough to be coherent. Too often, the left has allowed others to define it as a (usually) likeable gaggle, but inescapably a minority detached from what 'real people' actually think.

In 2016, when Corbyn was re-elected as Labour leader with an increased vote share, over 313,000 people voted for him to continue as party leader. That's 0.6% of Britons over 15 who were eligible to join as Labour Party members.

One does not win an election with 0.6%. But it is an impressive measure of an activist base willing to do more than the minimum – engaging in the internal processes of a political party, against hostile media coverage, to support policies of peace and social justice.

Add to that members of the Green Party, Trotskyist parties, Labour supporters excluded from voting, and many other currents of the British left, and comfortably over one in 160 people in Britain were on standby as an activist base to support these principles.

Labour's general election result in 2017 also showed electoral potential for a party on the left. People voted Labour for a variety of reasons in 2017 and 2019, but a left-wing leadership was not as fatal as some promised.

More recently, YouGov polling in July 2025 showed that 18% of Britons would have considered supporting a new left-wing party led by Jeremy Corbyn, which had yet to be launched. In retrospect, it was an asset for Your Party in July 2025 that it did not yet exist – but this seemed, at the time, an impressive level of support from a standing start.

Your Party revealed another important number pointing again to the left's activist base rather than its electoral support. When Zarah Sultana launched the first membership portal for Your Party, over 800,000 people signed up to express interest.

Signs of tension were already emerging, and the subsequent airing of mutual frustrations between Corbyn and Sultana – backed by threats of legal action – put a brake on this dynamic. It's possible the figure could have risen even higher. The activist base of the British left could therefore possibly approach 1m souls, a fact every activist and organiser should bear in mind.

The left's biggest weakness is that we have internalised our long-term depiction by our enemies. Whether we are sinister or loveable, the caricature is the same: unrepresentative hobbyists and eccentrics, curating a subculture rather than a counterculture capable of entering the mainstream of British society.

Even when the left led the Labour Party during the first coming of Corbynism and won every vote at conference on a general 'aye', factional bosses still acted as if they were leading a besieged minority. They met in secret, shirked big fights, and told activists to box smart and keep their powder dry.

From 2015 until 2019 (and, especially, in 2017) the Labour right was genuinely scared. I know, because I attended one of their conference fringes as a tourist in 2017, which was held in a basement as if to emphasise the bunker mentality. Fortunately for them, the leaders of Momentum, Unite and the office of the leader of the opposition chose to composite every motion until it became an empty consensus before it reached the conference floor.

More recently, the second coming of Corbynism has seen activist and electoral support for Your Party collapse – from 800,000 interested sign-ups and 18% of potential voters, to something under 30,000 paid-up members for a party that no longer registers in polls or the media. The latter, perhaps, is a small blessing. Such a dissipation of the potential to federate a mass of activists is almost unforgivable in its effects.

The point of this article is not to resolve questions of strategy nor to judge who is really on the left. Some will find others too liberal, or too sectarian, or too undisciplined, or too bureaucratic. The point is simply to assess who is ‘out there’ and to celebrate a reservoir of potential supporters with whom to learn from each other and to build a consensus around effective strategy and action. That could mean working with people even if we do not with them on something important to us.

The magic number is 800,000 – rounded up to one million if you include the Greens, Trotskyists, trade unionists, civil society organisers and countless others who didn't join the initial rush into Your Party. Every activist and organiser should keep that number in mind.

We are not a vanishing minority, and we should not act like one.