Summary of significant accounting policies - Basis of preparation (Details) |
Jun. 30, 2026
GBP (£)
|
Jun. 30, 2026
USD ($)
|
May 31, 2026
USD ($)
|
Jun. 30, 2025
GBP (£)
|
Jun. 30, 2025
USD ($)
|
|---|---|---|---|---|---|
| Going concern | |||||
| Cash resources | £ 67,246,000 | £ 86,105,000 | |||
| Borrowings | 688,954,000 | 636,974,000 | |||
| Senior secured notes | |||||
| Going concern | |||||
| Principal amount / Notional amount | $ | $ 550,000,000 | $ 425,000,000 | $ 425,000,000 | ||
| Borrowings | 408,942,000 | 308,914,000 | |||
| Secured term loan facility | |||||
| Going concern | |||||
| Principal amount / Notional amount | $ | $ 225,000,000 | $ 225,000,000 | |||
| Borrowings | 168,612,000 | 162,941,000 | |||
| Revolving facility | |||||
| Going concern | |||||
| Undrawn borrowing facility | 290,000,000 | 140,000,000 | |||
| Principal amount / Notional amount | 400,000,000 | ||||
| Borrowings | £ 110,000,000 | £ 160,000,000 |