Statement Of Financial Position [Abstract]
| Concept |
As at 2025-03-31 |
As at 2025-03-31 |
As at 2025-03-31 |
As at 2025-03-31 |
As at 2025-03-31 |
As at 2025-03-31 |
As at 2025-03-31 |
As at 2025-03-31 |
As at 2025-03-31 |
As at 2025-03-31 |
As at 2024-03-31 |
As at 2024-03-31 |
As at 2024-03-31 |
As at 2024-03-31 |
As at 2024-03-31 |
As at 2024-03-31 |
As at 2024-03-31 |
As at 2024-03-31 |
As at 2024-03-31 |
As at 2024-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
As at 2023-03-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | ||||||||||||||||||||||||||||||
| Assets [abstract] | ||||||||||||||||||||||||||||||
| Non-current assets [abstract] | ||||||||||||||||||||||||||||||
| Property, plant and equipment | — |
283,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
236,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Goodwill | — |
1,263,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
1,211,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Intangible assets other than goodwill | — |
576,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
569,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Deferred tax assets | — |
4,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
4,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Current tax assets, non-current | — |
–
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
14,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Non-current assets | — |
2,143,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
2,088,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Current assets [abstract] | ||||||||||||||||||||||||||||||
| Current inventories | — |
300,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
304,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Trade and other current receivables | — |
485,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
460,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Current tax assets, current | — |
14,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
2,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Cash and cash equivalents | — |
312,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
142,400,000
GBP
|
— | — |
168,500,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current assets | — |
1,115,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
911,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Assets | — |
3,258,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
2,999,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | ||||||||||||||||||||||||||||||
| Equity [abstract] | ||||||||||||||||||||||||||||||
| Issued capital | — |
38,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
38,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Retained earnings | — |
1,792,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
1,604,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Share premium | — |
23,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
23,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Treasury shares | — |
46,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
58,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Other reserves | — |
3,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
3,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Equity attributable to owners of parent | — |
1,899,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
1,736,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Non-controlling interests | — |
–
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
–
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Equity |
3,300,000
GBP
|
1,899,400,000
GBP
|
–
GBP
|
200,000
GBP
|
23,600,000
GBP
|
46,900,000
GBP
|
38,000,000
GBP
|
1,792,400,000
GBP
|
300,000
GBP
|
88,500,000
GBP
|
3,200,000
GBP
|
1,604,500,000
GBP
|
–
GBP
|
23,600,000
GBP
|
38,000,000
GBP
|
58,000,000
GBP
|
200,000
GBP
|
1,736,500,000
GBP
|
1,300,000
GBP
|
126,300,000
GBP
|
1,598,900,000
GBP
|
23,600,000
GBP
|
38,000,000
GBP
|
600,000
GBP
|
200,000
GBP
|
46,100,000
GBP
|
100,000
GBP
|
1,415,800,000
GBP
|
162,300,000
GBP
|
4,400,000
GBP
|
| Liabilities [abstract] | ||||||||||||||||||||||||||||||
| Non-current liabilities [abstract] | ||||||||||||||||||||||||||||||
| Non-current provisions [abstract] | ||||||||||||||||||||||||||||||
| Other non-current provisions | — |
11,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
10,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Trade and other non-current payables | — |
24,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
23,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Deferred tax liabilities | — |
73,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
79,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Non-current liabilities | — |
901,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
891,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Current liabilities [abstract] | ||||||||||||||||||||||||||||||
| Current provisions [abstract] | ||||||||||||||||||||||||||||||
| Current provisions | — |
44,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
35,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Trade and other current payables | — |
343,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
296,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Current tax liabilities, current | — |
10,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
18,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Current liabilities | — |
457,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
372,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Liabilities | — |
1,359,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
1,263,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |