| Clive Jonathan Mottram | Director | 15 Jun 2009 | 2 Jun 2010 | British | 67 years |
| David Lawrence Wilkinson | Director | 1 Dec 1992 | 31 Mar 1995 | British | 64 years |
| Deborah Grimason | Director | 13 Apr 2007 | 19 Jun 2009 | British | 63 years |
| Deborah Grimason | Director | 1 Jan 2012 | 20 Nov 2013 | British | 63 years |
| Dyfrig Morgan James | Director | 4 Apr 2003 | 7 Jan 2013 | British | 72 years |
| George Richard Phillipson | Director | 19 Jul 1994 | 16 Dec 1997 | British | 87 years |
| Gerald Michael Nolan Corbett | Director | 30 May 1992 | 1 Apr 1994 | British | 75 years |
| Howard Colin Hooper | Director | 7 Apr 1998 | 31 Oct 1998 | British | 67 years |
| Ian Maclean Reid | Director | 9 Sept 1998 | 4 Apr 2003 | British | 81 years |
| Jean Pierre Cloiseau | Director | 13 Feb 1998 | 30 Sept 1998 | French | 82 years |
| John Leivers | Director | 30 May 1992 | 31 Oct 1995 | British | 88 years |
| John Leivers | Director | 9 Sept 1998 | 30 Jun 2002 | British | 88 years |
| Marie-cecile Collignon | Director | 1 Sept 2011 | 31 Dec 2011 | French | 50 years |
| Martin Kenneth Riley | Director | 16 Apr 2013 | 4 May 2021 | British | 59 years |
| Michael John Choules | Director | 12 Sept 2014 | 9 Apr 2021 | British | 66 years |
| Nigel Clifford Jackson | Director | 30 Jun 2002 | 31 Dec 2004 | British | 73 years |
| Paul Francis William Cottrell | Director | 16 Apr 2013 | 26 Jul 2024 | British | 60 years |
| Peter William Joseph Mills | Director | 12 Nov 1996 | 1 Jun 1999 | British | 73 years |
| Raymond Alfred Elliott | Director | 9 Sept 1998 | 13 Apr 2007 | British | 79 years |
| Raymond Anthony Peacock | Director | 31 Oct 1995 | 12 Nov 1996 | British | 60 years |
| Rebecca Joan Powell | Director | 5 Jan 2011 | 1 Sept 2011 | British | 54 years |
| Richard James Chenery | Director | 30 May 1992 | 31 Jan 1998 | British | 87 years |
| Roger Martin White | Director | 30 May 1992 | 31 Oct 1995 | British | 75 years |
| Simon Michael Wallis | Director | 20 Sept 1993 | 31 Oct 1995 | British | 64 years |
| Simon Michael Wallis | Director | 23 Sept 1996 | 31 Oct 1998 | British | 64 years |
| Sonia Fennell | Director | 7 Jun 2010 | 5 Jan 2011 | British | 67 years |
| Stuart John Wykes | Director | 17 Jan 2005 | 17 Apr 2013 | British | 58 years |