Labour must hold its coalition of left and right together to stay in power and cannot risk becoming a minority party, John Denham said on Thursday in a call for unity before its conference in Brighton.

The communities secretary, considered one of the more Blairite members of the cabinet, made his remarks amid a fractious atmosphere before the week-long party gathering. Charles Clarke, former home secretary, warned on Wednesday that Labour faced a “bitter internecine conflict” if it was defeated at the general election.