| Michael Hugh Meacher | March 1974 | 1975 |
| James Gregor MacKenzie | March 1974 | June 1975 |
| Gerald Bernard Kaufman | 1975 | 1975 |
| Neil George Carmichael | December 1975 | April 1976 |
| George Robert Cryer | 1976 | 1978 |
| Robert Michael Marshall | May 1979 | 1981 |
| David Bower Mitchell | May 1979 | January 1981 |
| John Wakeham | 1981 | 1982 |
| John Roddick Russell MacGregor | 1981 | 1983 |