| Andrew David Briggs | Director | 6 Oct 2015 | 24 Apr 2019 | British | 60 years |
| Andrew Peter David Brem | Director | 6 Oct 2015 | 15 Dec 2017 | Swiss | 58 years |
| Angela Jane Darlington | Director | 7 Aug 2019 | 30 Apr 2021 | British | 58 years |
| Blair Mclaren Turnbull | Director | 7 Sept 2015 | 6 Jan 2020 | New Zealander | 56 years |
| Christopher Brian Wei | Director | 6 Oct 2015 | 31 Dec 2020 | Canadian | 59 years |
| Christopher John Clark | Director | 14 Mar 2018 | 20 Mar 2024 | British | 65 years |
| Claudia Isobel Arney | Director | 1 Jan 2017 | 31 Dec 2019 | British | 55 years |
| Colm Joseph Holmes | Director | 8 Aug 2019 | 1 Feb 2020 | Irish | 60 years |
| David Frederick Swiffen Rogers | Director | 20 Jan 2017 | 7 Oct 2020 | British | 70 years |
| David John Ramsay Mcmillan | Director | 6 Oct 2015 | 27 Feb 2017 | British | 60 years |
| Euan George Munro | Director | 6 Oct 2015 | 27 Feb 2017 | British | 56 years |
| Gareth John Hemming | Director | 23 Dec 2019 | 1 Nov 2022 | British | 56 years |
| Kathryn Anne Winup | Director | 7 Sept 2015 | 27 Jan 2017 | British | 56 years |
| Kirstine Ann Cooper | Director | 27 Feb 2017 | 28 Sept 2018 | British | 62 years |
| Maurice Ewen Tulloch | Director | 6 Oct 2015 | 11 Oct 2017 | British,canadian | 57 years |
| Nitinbhai Babubhai Maganbhai Amin | Director | 27 Feb 2017 | 30 Sept 2022 | British | 70 years |
| Robin Barker | Director | 28 Sept 2021 | 1 Aug 2022 | South African,italian | 54 years |
| Steve Bridger | Director | 18 Dec 2023 | 20 Aug 2025 | British | 55 years |
| Thomas James Latter | Director | 27 Apr 2020 | 6 Aug 2025 | British | 49 years |
| Tracey Louise Gration | Director | 15 Mar 2024 | 2 Apr 2025 | British | 57 years |