Wild steps up from his director role a year after joining from Nirex, the body responsible for the UK’s long-term nuclear waste management strategy, where he was director of comms.
He will work alongside agency founder Neil Lindsay in the new role.
Painter has stood down but will continue to work for the agency on a part-time basis. He is understood to be focusing his energies on getting selected to fight a Labour seat in the next general election.
Jefferson also lost director Dave Roberts, who is setting up his own public affairs agency.