The upcoming launch of a new party by Jeremy Corbyn and Zarah Sultana (Jeremy Corbyn and Zarah Sultana agree to launch leftwing party, 24 July) will inevitably prompt questions about whether this will divide the progressive vote or offer a genuine alternative to Labour’s centrist drift, especially as the Green party continues to grow as a principled voice for environmental and social justice. Although these projects are potential rivals, they need not be.

If the disturbing rise of rightwing populism is to be successfully confronted, the left must overcome fragmentation and find ways to coexist and collaborate. The Corbyn-Sultana initiative and the Greens share much common ground: a rejection of austerity, commitment to democratic reform and a belief in economic and ecological justice. Their differences in emphasis, tone and priorities are real but not irreconcilable.

There has to be scope for a non-aggression pact at the next general election, with each party standing aside in constituencies where the other has a better chance of success. Joint campaigning on core issues – such as proportional representation, protest rights, wealth taxes and a green new deal – could amplify their impact, and framing climate action as central to economic justice, not separate from it, could provide a unifying narrative for both.

This is not about merging or blurring identities. It is about strategic and political maturity. If the left cannot cooperate when so much is at stake, it will surrender the field to those who thrive on division and fear. Unity does not require uniformity; it requires courage and purpose. The worse case, of a public war of words and clashing candidacies between the Greens and Corbynites, would demoralise voters and hand the initiative to the populist right.
Patrick Cosgrove
Chapel Lawn, Shropshire

Your report quotes Labour party sources who are dismissive of the threat from Jeremy Corbyn and then bluntly states that Corbyn “lost the 2017 and 2019 elections as party leader”. It would have provided a fairer context if you had pointed out that in 2017, the Corbyn-led Labour party achieved 2.5m more votes (and a 6% higher vote share) than Keir Starmer did in 2024. Even in 2019, 500,000 more people voted for Corbyn’s party than Starmer’s.
Dr Chris Morris
Kidderminster, Worcestershire

In the winter election of 2019 I spent hours leafleting for Jeremy Corbyn’s Labour party. The sensation of cold and wet letterboxes still lingers on my fingertips when I think of what he said in an Observer article just after the election – that Labour had lost the election but won the argument. This is all Mr Corbyn is interested in doing – winning the argument – and indeed I think he will find that is all he ever will win.
Ross Armstrong
Chester

Thank you to Jeremy Corbyn for still caring enough and having the humanity to rally the 99% to join together and put 40 years of neoliberal theft and exploitation behind us. I support all his domestic policies, but the realpolitik of foreign policy bothers me. How would he deal with Vladimir Putin and Benjamin Netanyahu?
Pamela Hope
Kingston upon Thames, London

Oh, Jeremy Corbyn, why splinter the left further by creating a new party when the Greens already actively stand and work for all you want to fight for?
Sushila Dhall
Oxford