Statement Of Financial Position [Abstract]
| Concept |
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 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
As at 2022-03-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | |||||||||||||||||||||
| Assets [abstract] | |||||||||||||||||||||
| Non-current assets [abstract] | |||||||||||||||||||||
| Property, plant and equipment | — | — | — | — | — |
180,900,000
GBP
|
— | — |
186,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Right-of-use assets | — | — | — | — | — |
72,800,000
GBP
|
— | — |
46,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Deferred tax assets | — | — | — | — | — |
9,500,000
GBP
|
— | — |
6,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Non-current assets | — | — | — | — | — |
1,257,000,000
GBP
|
— | — |
953,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Current assets [abstract] | |||||||||||||||||||||
| Current inventories | — | — | — | — | — |
656,000,000
GBP
|
— | — |
616,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Trade and other current receivables | — | — | — | — | — |
701,400,000
GBP
|
— | — |
692,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Cash and cash equivalents | — | — | — | — | — |
96,000,000
GBP
|
— | — |
120,500,000
GBP
|
— | — | — | — | — | — | — | — |
158,400,000
GBP
|
— | — | — |
| Current assets | — | — | — | — | — |
1,641,400,000
GBP
|
— | — |
1,590,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Assets | — | — | — | — | — |
2,898,400,000
GBP
|
— | — |
2,544,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | |||||||||||||||||||||
| Equity [abstract] | |||||||||||||||||||||
| Retained earnings | — | — | — | — | — |
1,038,900,000
GBP
|
— | — |
954,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Treasury shares | — | — | — | — | — |
1,800,000
GBP
|
— | — |
2,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Other reserves | — | — | — | — | — |
108,300,000
GBP
|
— | — |
108,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Equity attributable to owners of parent | — | — | — | — | — |
1,432,300,000
GBP
|
— | — |
1,344,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Non-controlling interests | — | — | — | — | — |
600,000
GBP
|
— | — |
700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Equity |
108,300,000
GBP
|
1,432,300,000
GBP
|
1,038,900,000
GBP
|
600,000
GBP
|
1,800,000
GBP
|
1,432,900,000
GBP
|
286,900,000
GBP
|
1,344,200,000
GBP
|
1,344,900,000
GBP
|
2,200,000
GBP
|
700,000
GBP
|
954,300,000
GBP
|
283,300,000
GBP
|
108,800,000
GBP
|
3,000,000
GBP
|
1,108,500,000
GBP
|
772,800,000
GBP
|
— |
–
GBP
|
278,500,000
GBP
|
60,200,000
GBP
|
| Liabilities [abstract] | |||||||||||||||||||||
| Non-current liabilities [abstract] | |||||||||||||||||||||
| Non-current provisions [abstract] | |||||||||||||||||||||
| Other non-current provisions | — | — | — | — | — |
4,200,000
GBP
|
— | — |
4,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Deferred tax liabilities | — | — | — | — | — |
103,300,000
GBP
|
— | — |
90,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Non-current liabilities | — | — | — | — | — |
650,200,000
GBP
|
— | — |
360,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Current liabilities [abstract] | |||||||||||||||||||||
| Current provisions [abstract] | |||||||||||||||||||||
| Other current provisions | — | — | — | — | — |
5,000,000
GBP
|
— | — |
1,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Trade and other current payables | — | — | — | — | — |
602,700,000
GBP
|
— | — |
658,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Current liabilities | — | — | — | — | — |
815,300,000
GBP
|
— | — |
838,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Liabilities | — | — | — | — | — |
1,465,500,000
GBP
|
— | — |
1,199,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |