| Sir John Anthony Grant | October 1970 | 1972 |
| Patrick Edmund Pery, Earl of Limerick | April 1972 | 1974 |
| Eric Petro Deakins | March 1974 | April 1976 |
| Stanley Clinton Davis | 4 March 1974 | 4 May 1979 |
| Michael Hugh Meacher | 1976 | May 1979 |
| Reginald Edwin Eyre | May 1979 | |
| Norman Beresford Tebbit | May 1979 | 5 January 1981 |
| Iain MacDonald Sproat | September 1981 | 10 June 1983 |