Exclusive: Andy Burnham-backed Mainstream group will inevitably influence looming deputy leadership contest

Keir Starmer is facing fresh pressure from Labour insiders, days after a sweeping government reshuffle, as party figures from the left and centre mobilise through a network, backed by Andy Burnham, designed to change Labour’s direction.

The network, called Mainstream, will inevitably influence Labour’s looming deputy leadership contest, with organisers already throwing their weight behind former cabinet minister Louise Haigh who is understood to be informally linked to the group, as well as Lucy Powell, the former Commons leader.

Mainstream has been steered by Compass, a centre-left thinktank, and is backed by Burnham, the Greater Manchester mayor who when asked did not rule out the possibility of running in a future leadership contest with the network’s support.

But supporters include figures right across the party from Labour’s left to the centre, including Labour peers Alf Dubs and Anna Healy, Labour MPs Clive Lewis, Dawn Butler, Alex Sobel, Clive Efford, chair of the Tribune group of MPs, the former Blairite minister John Denham, and the founder of Momentum, Jon Lansman.