News of Brunswick's hire of Kate Fall comes the day after the world's largest PR firm Edelman took on another former Cameron staffer, Robin Gordon-Farleigh, and makes it the latest in a string of PR agencies looking to boost its public affairs and political nous for 2017.
Fall was deputy chief of staff to David Cameron between 2010 and 2016. She was also seconded to the Stronger In campaign for a month ahead of last year's EU Referendum, and is a serving peer, having joined the Conservative benches of the House of Lords in October 2015.
She has taken on a part-time paid role as a senior adviser to Brunswick Group, as revealed by the Government's business appointments watchdog.
Fall started work with the firm last year, and the letter from the Advisory Committee on Business Appointments (ACOBA) permitting the hire has now been published.
Simon Sporborg, UK managing partner at Brunswick since 2014, said: "Kate joined us in November 2016, primarily to support our recruitment initiatives and help us expand our network of talent, including world-class public affairs capabilities, across Europe."
ACOBA said in its letter that as per the Government's business appointment rules, Fall should not "draw on any privileged information available to her from her time in Crown service" or become "personally involved" in lobbying the UK Government.