Best Prime Minister: Opinium
| End Date | Company | Client | CON | LAB | OTH | DK | Lead |
| 20 Sep 2018 | Opinium Online | 33 | 23 | 36 | 9 | +3 | |
| 13 Sep 2018 | Opinium Online | 32 | 23 | 35 | 10 | +3 | |
| 17 Aug 2018 | Opinium Online | Obsever | 30 | 24 | 46 | +6 | |
| 13 Jul 2018 | Opinium Online | Obsever | 29 | 25 | 36 | 10 | +7 |
| 07 Jun 2018 | Opinium Online | 35 | 25 | 29 | 11 | +6 | |
| 16 May 2018 | Opinium Online | Obsever | 36 | 23 | 30 | 10 | +6 |
| 12 Apr 2018 | Opinium Online | 36 | 24 | 31 | 9 | +5 | |
| 15 Mar 2018 | Opinium Online | Observer | 34 | 26 | 29 | 11 | +5 |
| 08 Feb 2018 | Opinium Online | Observer | 34 | 28 | 28 | 10 | +6 |
| 12 Jan 2018 | Opinium Online | Observer | 33 | 28 | 29 | 11 | +4 |
| 14 Dec 2017 | Opinium Online | Observer | 34 | 28 | 27 | 11 | +6 |
| 16 Nov 2017 | Opinium Online | 14–16 Nov | 34 | 29 | 27 | 10 | +5 |
| 06 Oct 2017 | Opinium Online | Observer | 32 | 29 | 28 | 11 | +3 |
| 22 Sep 2017 | Opinium Online | 36 | 26 | 28 | 10 | +8 | |
| 15 Sep 2017 | Opinium Online | Observer | 36 | 28 | 26 | 11 | +8 |
| 18 Aug 2017 | Opinium Online | 34 | 30 | 27 | 9 | +4 | |
| 14 Jul 2017 | Opinium Online | 36 | 33 | 22 | 9 | +3 | |
| 29 Jun 2017 | Opinium Online | Observer | 35 | 34 | 23 | 8 | +1 |