The Omnicom agency successfully defended the business against WPP’s MediaCom and another undisclosed agency.
Manning Gottlieb will now continue its work on the DWP’s 'I’m In' campaign, on which the department plans to spend £8m.
The campaign launched in September 2012 and has starred celebrity bosses including Theo Paphitis of ‘Dragon’s Den’ and Karren Brady from ‘The Apprentice’.
The TV and print campaign, created by Adam&eve/DDB, aims to educate businesses about sweeping pensions changes that mean employers now automatically enrol their workers into a pension if they meet certain criteria.
Robert Ffitch, the chief executive of Manning Gottlieb OMD, said: "We are incredibly proud to have won this competitive pitch for a campaign of such high national importance, and are looking forward to continuing our on-going relationship with DWP."
Manning Gottlieb won the media planning brief in October 2011, following a pitch against PHD and MEC.
Media buying for the campaign will continue to be handled by Group M’s M4C.