According to sources close to the party, it was felt Norman ‘wasn't forceful enough' in driving home the Lib Dems' key messages.
Lib Dems CEO Lord Rennard told PRWeek: ‘During David's time as director of policy and comms, he oversaw the growth of the media team to an all-time high, with the amalgamation of our research and policy functions and stronger co-ordination of our policy and press work. Having secured these changes, David decided now was an appropriate time to leave.'
The party is thought likely to recruit a replacement to help it take on a resurgent Conservative Party and a post-Blair government.
Meanwhile, head of press Mark Littlewood manages the 14-strong media team, while Greg Simpson oversees a further 14 policy and research staff. Burson-Marsteller UK chairman Gavin Grant also acts as a comms adviser.
Puja Darbari became Campbell's press secretary in August, joining from The Forster Company. Norman, unavailable for comment, joined in February from WWF.
