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 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 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 |
As at 2023-03-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | |||||||||||||||||||||||||||||||||
| Assets [abstract] | |||||||||||||||||||||||||||||||||
| Non-current assets [abstract] | |||||||||||||||||||||||||||||||||
| Property, plant and equipment |
18,824,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
16 ,61 1 . 5
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Investments accounted for using equity method |
1,9 87 .3
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
1, 963.2
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Non-current assets |
25,266 .2
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
22,911. 3
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Current assets [abstract] | |||||||||||||||||||||||||||||||||
| Current inventories |
462,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
343 .0
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Trade and other current receivables |
2,9 43 .2
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
2,654,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Cash and cash equivalents |
1,0 90 .5
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
1,0 35 .9
GBP
|
— | — | — | — | — |
891. 8
GBP
|
— | — | — | — | — | — | — | — | — | — |
| Current assets |
5,09 7 .4
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
5,358,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Assets |
30,363 .6
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
28, 270 . 2
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | |||||||||||||||||||||||||||||||||
| Equity [abstract] | |||||||||||||||||||||||||||||||||
| Issued capital |
555,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
548,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Retained earnings |
8,336,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
7, 5 4 0 . 0
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Share premium |
81 2.6
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
820. 1
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Non-controlling interests |
628. 8
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
55 4.9
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Equity |
12,69 2.8
GBP
|
628 .8
GBP
|
52 .6
GBP
|
81 2. 6
GBP
|
555,600,000
GBP
|
8, 336.7
GBP
|
1 ,8 82 .4
GBP
|
10, 181 .6
GBP
|
12 ,06 4.0
GBP
|
432 .7
GBP
|
8,600,000
GBP
|
7,540,000,000
GBP
|
554. 9
GBP
|
820. 1
GBP
|
5 48. 1
GBP
|
52,600,000
GBP
|
11,803 .1
GBP
|
1 , 882 .4
GBP
|
9,365. 8
GBP
|
407 .6
GBP
|
11 , 248. 2
GBP
|
2 .6
GBP
|
1 1,0 83. 2
GBP
|
82 1. 2
GBP
|
547 .0
GBP
|
52,600,000
GBP
|
10,629,100,000
GBP
|
1 ,882 .4
GBP
|
441 .2
GBP
|
8,746,700,000
GBP
|
6 ,852 .6
GBP
|
454 .1
GBP
|
32,100,000
GBP
|
| Liabilities [abstract] | |||||||||||||||||||||||||||||||||
| Non-current liabilities [abstract] | |||||||||||||||||||||||||||||||||
| Non-current provisions [abstract] | |||||||||||||||||||||||||||||||||
| Non-current provisions |
676. 1
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
712,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Trade and other non-current payables |
1,2 4 7 .9
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
1,0 92 .8
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Deferred tax liabilities |
1,8 44 . 5
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
1,536. 8
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Other non-current financial liabilities |
23. 1
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
36,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Non-current liabilities |
12,599 .7
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
11,6 06.3
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Current liabilities [abstract] | |||||||||||||||||||||||||||||||||
| Current provisions [abstract] | |||||||||||||||||||||||||||||||||
| Current provisions |
80,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
52,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Trade and other current payables |
2,8 9 7 .9
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
3, 32 2. 5
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Other current financial liabilities |
2,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
3,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Current liabilities |
5,071,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
4,860. 8
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Liabilities |
17 ,670.8
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
16 ,4 67 . 1
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |