Lease liabilities - Reconciliation of the finance lease creditors (Details) - GBP (£) £ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Reconciliation of undiscounted lease payments to net investment in finance lease [abstract] | ||
| Beginning balance | £ 2,201 | £ 2,620 |
| Additions | 1,847 | 196 |
| Interest element of payments to lease creditors | (194) | (156) |
| Principal element of payments to lease creditors | (843) | (615) |
| Interest expense of leases | 194 | 156 |
| Ending balance | £ 3,205 | £ 2,201 |