| Norman Peter Lamb | 3 February 2012 | 4 September 2012 |
| Joanne Kate Swinson | 4 September 2012 | 8 May 2015 |
| Jonathan Peter Marland, Baron Marland | 5 September 2012 | 8 January 2013 |
| James Edward George Younger, Viscount Younger of Leckie | 9 January 2013 | 17 July 2014 |
| George William Freeman | 15 July 2014 | 17 July 2016 |
| Richard Irwin Harrington | 14 June 2017 | 25 March 2019 |
| Andrew George Stephenson | 4 April 2019 | 25 July 2019 |