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 | — | — | — | — | — | — |
1,430,513,000
GBP
|
— |
1,354,806,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Right-of-use assets | — | — | — | — | — | — |
349,925,000
GBP
|
— |
336,221,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Goodwill | — | — | — | — | — | — |
2,190,147,000
GBP
|
— |
2,029,620,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Intangible assets other than goodwill | — | — | — | — | — | — |
946,798,000
GBP
|
— |
928,009,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Investments accounted for using equity method | — | — | — | — | — | — |
32,825,000
GBP
|
— |
47,789,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Deferred tax assets | — | — | — | — | — | — |
81,258,000
GBP
|
— |
69,053,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Non-current assets | — | — | — | — | — | — |
5,074,226,000
GBP
|
— |
4,854,697,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Current assets [abstract] | |||||||||||||||||||||
| Current inventories | — | — | — | — | — | — |
1,072,061,000
GBP
|
— |
1,192,803,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Trade and other current receivables | — | — | — | — | — | — |
2,172,422,000
GBP
|
— |
2,312,269,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Cash and cash equivalents | — | — | — | — | — | — |
1,109,446,000
GBP
|
— |
1,421,749,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Current assets | — | — | — | — | — | — |
4,408,993,000
GBP
|
— |
4,986,079,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Assets | — | — | — | — | — | — |
9,483,219,000
GBP
|
— |
9,840,776,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | |||||||||||||||||||||
| Equity [abstract] | |||||||||||||||||||||
| Issued capital | — | — | — | — | — | — |
17,422,000
GBP
|
— |
17,422,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Retained earnings | — | — | — | — | — | — |
2,078,568,000
GBP
|
— |
1,941,223,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Share premium | — | — | — | — | — | — |
883,890,000
GBP
|
— |
883,669,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Other reserves | — | — | — | — | — | — |
932,000
GBP
|
— |
932,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Equity attributable to owners of parent | — | — | — | — | — | — |
3,091,391,000
GBP
|
— |
2,978,091,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Non-controlling interests | — | — | — | — | — | — |
91,641,000
GBP
|
— |
80,219,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Equity |
111,511,000
GBP
|
3,091,391,000
GBP
|
2,078,568,000
GBP
|
91,641,000
GBP
|
883,890,000
GBP
|
17,422,000
GBP
|
3,183,032,000
GBP
|
2,978,091,000
GBP
|
3,058,310,000
GBP
|
883,669,000
GBP
|
17,422,000
GBP
|
80,219,000
GBP
|
1,941,223,000
GBP
|
135,777,000
GBP
|
2,905,184,000
GBP
|
17,422,000
GBP
|
883,321,000
GBP
|
1,783,033,000
GBP
|
2,970,563,000
GBP
|
65,379,000
GBP
|
221,408,000
GBP
|
| Liabilities [abstract] | |||||||||||||||||||||
| Non-current liabilities [abstract] | |||||||||||||||||||||
| Non-current provisions [abstract] | |||||||||||||||||||||
| Non-current provisions | — | — | — | — | — | — |
306,367,000
GBP
|
— |
301,067,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Deferred tax liabilities | — | — | — | — | — | — |
286,217,000
GBP
|
— |
263,623,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Non-current liabilities | — | — | — | — | — | — |
2,561,021,000
GBP
|
— |
2,889,319,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Current liabilities [abstract] | |||||||||||||||||||||
| Current provisions [abstract] | |||||||||||||||||||||
| Current provisions | — | — | — | — | — | — |
67,011,000
GBP
|
— |
52,349,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Trade and other current payables | — | — | — | — | — | — |
3,054,108,000
GBP
|
— |
3,279,898,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Current liabilities | — | — | — | — | — | — |
3,739,166,000
GBP
|
— |
3,893,147,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Liabilities | — | — | — | — | — | — |
6,300,187,000
GBP
|
— |
6,782,466,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
| Equity and liabilities | — | — | — | — | — | — |
9,483,219,000
GBP
|
— |
9,840,776,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |