Statement Of Financial Position [Abstract]
| Concept |
As at 2023-04-01 |
As at 2023-04-01 |
As at 2023-04-01 |
As at 2023-04-01 |
As at 2023-04-01 |
As at 2023-04-01 |
As at 2023-04-01 |
As at 2022-04-02 |
As at 2022-04-02 |
As at 2022-04-02 |
As at 2022-04-02 |
As at 2022-04-02 |
As at 2022-04-02 |
As at 2022-04-02 |
As at 2021-04-03 |
As at 2021-04-03 |
As at 2021-04-03 |
As at 2021-04-03 |
As at 2021-04-03 |
As at 2021-04-03 |
As at 2021-04-01 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | |||||||||||||||||||||
| Assets [abstract] | |||||||||||||||||||||
| Non-current assets [abstract] | |||||||||||||||||||||
| Property, plant and equipment | — | — |
185,900,000
GBP
|
— | — | — | — | — | — | — | — | — |
190,900,000
GBP
|
— | — | — | — | — | — | — | — |
| Goodwill | — | — |
680,300,000
GBP
|
— | — | — | — | — | — | — | — | — |
646,000,000
GBP
|
— | — | — | — | — | — | — | — |
| Intangible assets other than goodwill | — | — |
294,400,000
GBP
|
— | — | — | — | — | — | — | — | — |
293,500,000
GBP
|
— | — | — | — | — | — | — | — |
| Deferred tax assets | — | — |
22,400,000
GBP
|
— | — | — | — | — | — | — | — | — |
23,100,000
GBP
|
— | — | — | — | — | — | — | — |
| Non-current assets | — | — |
2,143,100,000
GBP
|
— | — | — | — | — | — | — | — | — |
2,302,200,000
GBP
|
— | — | — | — | — | — | — | — |
| Current assets [abstract] | |||||||||||||||||||||
| Current inventories | — | — |
93,700,000
GBP
|
— | — | — | — | — | — | — | — | — |
78,100,000
GBP
|
— | — | — | — | — | — | — | — |
| Trade and other current receivables | — | — |
103,900,000
GBP
|
— | — | — | — | — | — | — | — | — |
96,500,000
GBP
|
— | — | — | — | — | — | — | — |
| Cash and cash equivalents | — | — |
64,400,000
GBP
|
— | — | — | — | — | — | — | — | — |
54,300,000
GBP
|
— | — | — | — | — | — | — | — |
| Current assets | — | — |
262,800,000
GBP
|
— | — | — | — | — | — | — | — | — |
231,300,000
GBP
|
— | — | — | — | — | — | — | — |
| Assets | — | — |
2,405,900,000
GBP
|
— | — | — | — | — | — | — | — | — |
2,533,500,000
GBP
|
— | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | |||||||||||||||||||||
| Equity [abstract] | |||||||||||||||||||||
| Issued capital | — | — |
86,800,000
GBP
|
— | — | — | — | — | — | — | — | — |
86,300,000
GBP
|
— | — | — | — | — | — | — | — |
| Retained earnings | — | — |
974,300,000
GBP
|
— | — | — | — | — | — | — | — | — |
1,076,700,000
GBP
|
— | — | — | — | — | — | — | — |
| Share premium | — | — |
2,500,000
GBP
|
— | — | — | — | — | — | — | — | — |
1,500,000
GBP
|
— | — | — | — | — | — | — | — |
| Equity |
3,400,000
GBP
|
86,800,000
GBP
|
1,406,000,000
GBP
|
974,300,000
GBP
|
2,500,000
GBP
|
351,700,000
GBP
|
9,300,000
GBP
|
351,700,000
GBP
|
9,300,000
GBP
|
1,076,700,000
GBP
|
1,500,000
GBP
|
86,300,000
GBP
|
1,506,900,000
GBP
|
3,300,000
GBP
|
9,300,000
GBP
|
755,100,000
GBP
|
351,700,000
GBP
|
1,183,600,000
GBP
|
85,500,000
GBP
|
600,000
GBP
|
3,700,000
GBP
|
| Liabilities [abstract] | |||||||||||||||||||||
| Non-current liabilities [abstract] | |||||||||||||||||||||
| Non-current provisions [abstract] | |||||||||||||||||||||
| Non-current provisions | — | — |
6,600,000
GBP
|
— | — | — | — | — | — | — | — | — |
8,300,000
GBP
|
— | — | — | — | — | — | — | — |
| Deferred tax liabilities | — | — |
177,900,000
GBP
|
— | — | — | — | — | — | — | — | — |
212,900,000
GBP
|
— | — | — | — | — | — | — | — |
| Non-current liabilities | — | — |
727,600,000
GBP
|
— | — | — | — | — | — | — | — | — |
767,900,000
GBP
|
— | — | — | — | — | — | — | — |
| Current liabilities [abstract] | |||||||||||||||||||||
| Current provisions [abstract] | |||||||||||||||||||||
| Current provisions | — | — |
13,300,000
GBP
|
— | — | — | — | — | — | — | — | — |
2,300,000
GBP
|
— | — | — | — | — | — | — | — |
| Trade and other current payables | — | — |
255,400,000
GBP
|
— | — | — | — | — | — | — | — | — |
254,000,000
GBP
|
— | — | — | — | — | — | — | — |
| Current liabilities | — | — |
272,300,000
GBP
|
— | — | — | — | — | — | — | — | — |
258,700,000
GBP
|
— | — | — | — | — | — | — | — |
| Liabilities | — | — |
999,900,000
GBP
|
— | — | — | — | — | — | — | — | — |
1,026,600,000
GBP
|
— | — | — | — | — | — | — | — |