Soft left group Open Labour has merged with Mainstream after a vote at their Extraordinary General Meeting held yesterday (Saturday 8th August 2026). Members of Open Labour voted 78.6% in favour of the move with 21.4% opposing it. Mainstream was set up in September 2025 with support from now Prime Minister Andy Burnham as well as Open Labour and Compass. Kerry Postlewhite, Chair of Mainstream said: “This is a historic moment, today we unite as the most organised, energetic force for democratic socialism the Labour Party has seen in a generation. A spokesperson for Open Labour said; “Open Labour has achieved so much over the past decade, championing democracy, pluralism, liberation and an internationalist politics within our party.