Whilst sitting as an MP he was a non-executive director of Mid Kent Water from 2005 to 2007, and of the successor company South East Water until 2010. Between July 2009 and February 2010, Green was paid £16,666.64 for 112 hours by South East Water for "attending meetings and offering advice" according to the House of Commons Record of Members Interests. He returned to the frontbench under the leadership of David Cameron in 2005 as a spokesman on home affairs and shadow minister for immigration.