Brigadier (Retd) Jon Brittain is a partner at defence and security lobbyists Terrington Management, who joined the firm after 32 years of service in various army and defence positions.
His last position before his official retirement in February 2016 was as head of defence logistics and the Joint Forces Command – which brings together air, sea and land forces.
No need for ACOBA to approve move to defence lobbying firm
According to Private Eye magazine, Brittain took up his new Terrington job on 19 December 2015, before he had officially left the civil service. His role was not required to be vetted by the Advisory Committee on Business Appointments, but by MOD bosses instead.
Terrington, however, state on their website that Brittain joined in January 2016 and Companies House records show him as being appointed a director of Terrington on 1 January 2016, the day after Terrington co-founder Geoffrey Pattie resigned as a company director.  His biography highlights that he has 'broad experience in the UK MOD in the fields of acquisition, support and technology, and was the sponsor for equipment ranging from helicopters, amphibious shipping, strategic and tactical airlift, logistic vehicles, deployable infrastructure and support shipping. 
- Richard Brooks and Solomon Hughes Revolving Doors Special: PUBLIC SERVANTS, PRIVATE PAYDAYS How ministers and mandarins make life after government pay, Private Eye, 28 July 2016
- Terrington Management, Companies House
- About, Terrington, last accessed 14 September 2017