| Goronwy Owen Roberts | August 1967 | October 1969 |
| Rt Hon Alun Arthur Gwynne Jones, Baron Chalfont | 17 October 1968 | 19 June 1970 |
| Rt Hon Harold Julian Amery | 1970 | February 1974 |
| Rt Hon Joseph Bradshaw Godber | June 1970 | 1972 |
| Rt Hon Robert Alexander Lindsay, Baron Balniel | 5 November 1972 | 4 March 1974 |
| William Armand Thomas Tristan Garel-Jones | 28 November 1990 | 27 May 1993 |
| Douglas Martin Hogg | 28 November 1990 | 5 July 1995 |
| Rt Hon Alastair Robertson Goodlad | 14 April 1992 | 5 July 1995 |