As David settles into life as a Labour backbencher, Lisa Tremble has started work at lobbying firm Lexington Communications after handling comms for the elder Miliband's campaign.
The news comes as his brother Ed finalises his comms team, with high-profile positions expected for his campaign staffers Polly Billington and Stewart Wood.
Tremble will become a director at Lexington, working on corporate and public affairs clients, but partner Ian Kennedy said that no specific clients had yet been assigned to her.
'Lisa has a good background in politics and has worked in-house as well,' said Kennedy. 'She was probably one of the best special advisers in government, but she also has corporate ability.'
Kennedy added that Lexington had made Tremble an offer earlier in the year, but this was delayed so that she could work on Miliband's campaign.
Tremble has formerly worked as a special adviser to former culture secretary James Purnell and as head of comms at the soon-to-be-abolished UK Film Council.
Jo Tanner, who worked on Andy Burnham's leadership campaign, is thought to be looking for a new job. Tanner was formerly the Freight Transport Association's director of comms.
GallieGodfrey co-founder Jim Godfrey, who worked on David Miliband's campaign, said most of his campaign staff were contemplating their next moves.
'The campaign was a crossroads moment for the Labour Party, for David, but also for a lot of people who worked for him,' said Godfrey. 'A lot of people are taking some time to think about what they plan to do next.'
Other members of David Miliband's team included online comms manager Jessica Asato. Ed Balls' campaign included press secretary Alex Belardinelli, who is expected to continue working for Balls. Balls is in the running for a senior shadow cabinet position, expected to be announced on 7 October.