GORTON and Denton tomorrow votes in a by-election with far-reaching consequences.

Will the loss of a safe Labour seat deal another blow to the already reeling Keir Starmer government, or will he get a temporary reprieve? Will the Greens win, further fuelling the rise of Zack Polanski’s insurgents? Will a Reform candidate with a record of attacks on non-white Britons, immigrants and Muslims confirm Britain’s trajectory is towards an ever more openly racist future?

Any of those things could happen, which is a dilemma for the left. Most would agree the Reform candidate must be stopped. But the luxury of an obvious “stop Reform” unity candidate is not always afforded us.

Even in Caerphilly, where Plaid Cymru’s stunning win in October exploded Labour’s claim to be the default Stop Reform option, this was not clear in advance. Gorton and Denton is too close to call: the top three neck and neck, the Greens slightly ahead but well within margins of error. Both Labour and the Greens say that only a vote for them can do it; the truth is that either of them might, and either might not.

The Morning Star has already indicated our call for a Green vote in this by-election. Stopping Reform in this seat is not the only consideration: stopping the rise of the far right nationally means breaking with Donald Trump’s lawless regime in Washington, confronting the demonisation of immigrants and refugees, and unpicking the corporate stitch-up that British politics has become, driving alienation and public anger.

Removing Keir Starmer from office is a prerequisite for all of that, and Labour losing the seat will hasten his exit.

A win for the Greens would also discredit Labour attempts to paint criticism of its foreign policy as beyond the pale: attacks on them for raising Gaza, as fuelling “communal tensions,” are just a bid to evade responsibility for the government’s complicity in genocide, which needs to have electoral consequences.

Nonetheless, the three-horse race points to our need to build a bigger and more persuasive movement to defeat the far right — not just by denying it a by-election win but by halting and reversing its advance.

Advocates of a “progressive alliance” on an anyone-but-Reform basis should look to the experience in France or Germany, where these alliances have shown diminishing returns. They sometimes keep the far right from office but the cost is the growth of a “they’re all the same” attitude which fuels its continuing rise. Actual advances for the left — as in France’s last National Assembly election — come when it refuses to shore up the hated status quo and offers a combative alternative.

Sometimes we need to vote tactically to block a far-right win.

We should still think strategically about the bigger problem, that the far right is competitive at all, especially since contests like this will certainly recur, where the shrewdest “stop Reform” vote is unclear.

Gathering everyone not currently on the far right under one umbrella, even where possible, doesn’t solve that problem.

But it is not beyond our reach to solve: the scale of the Palestine demonstrations, the mass mobilisations against the racist riots of summer 2024, even the 2017 surge in Labour votes in unexpected areas from the deindustrialised north, where it had long been in decline, to Tory Canterbury and Cornwall show it is possible to change people’s minds.

Reform are making it still more possible, by their adoption of wholesale Tory economics that target the worker, the pensioner, the renter in the private sector.

Winning right-wing voters to the left is perfectly plausible.

That is, if the left is radical enough to be a convincing threat to the status quo; outward-looking enough to reject the divisions of identity politics; and community-rooted enough to talk to people who are not, yet, on the left.