Open Labour merges into Mainstream

In internal Labour news, Open Labour, the soft left activist group, has merged with Mainstream after a vote at their Extraordinary General Meeting held yesterday.

Members of Open Labour voted 78.6% in favour of the move with 21.4% opposing it.

Mainstream was co-founded by Open Labour and Compass and launched by Andy Burnham in September 2025.

According to the founders of Mainstream, it is intended to serve as a broad-church for Labour’s progressive left and was seen to be supportive of Andy Burnham.

The group says it is the home for Labour’s “radical realists” and is “serious about winning a democratic socialist future”.

Kerry Postlewhite, Chair of Mainstream told LabourList: “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. In less than a year, Mainstream has grown our membership and shown we can create the change our party desperately needs. I don’t think it is an overstatement to say this is the most organised the soft left has been for decades.”

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. But this is a moment that calls for us to be stronger together. I’m incredibly proud that our members have voted to merge with Mainstream and excited to carry our values and political tradition into this next chapter.”