Statement Of Financial Position [Abstract]
| Concept |
As at 2024-12-31 |
As at 2024-12-31 |
As at 2024-12-31 |
As at 2024-12-31 |
As at 2024-12-31 |
As at 2024-12-31 |
As at 2023-12-31 |
As at 2023-12-31 |
As at 2023-12-31 |
As at 2023-12-31 |
As at 2023-12-31 |
As at 2023-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | ||||||||||||||||||
| Assets [abstract] | ||||||||||||||||||
| Non-current assets [abstract] | ||||||||||||||||||
| Property, plant and equipment | — | — | — |
1,082,900,000
GBP
|
— | — | — | — | — |
1,044,000,000
GBP
|
— | — | — | — | — | — | — | — |
| Right-of-use assets | — | — | — |
85,000,000
GBP
|
— | — | — | — | — |
87,500,000
GBP
|
— | — | — | — | — | — | — | — |
| Investments accounted for using equity method | — | — | — |
1,900,000
GBP
|
— | — | — | — | — |
1,900,000
GBP
|
— | — | — | — | — | — | — | — |
| Deferred tax assets | — | — | — |
14,700,000
GBP
|
— | — | — | — | — |
14,400,000
GBP
|
— | — | — | — | — | — | — | — |
| Non-current assets | — | — | — |
2,625,100,000
GBP
|
— | — | — | — | — |
2,669. 8
GBP
|
— | — | — | — | — | — | — | — |
| Current assets [abstract] | ||||||||||||||||||
| Current inventories | — | — | — |
367,900,000
GBP
|
— | — | — | — | — |
341,200,000
GBP
|
— | — | — | — | — | — | — | — |
| Trade and other current receivables | — | — | — |
349,500,000
GBP
|
— | — | — | — | — |
395,700,000
GBP
|
— | — | — | — | — | — | — | — |
| Cash and cash equivalents | — | — | — |
166,800,000
GBP
|
— | — | — | — | — |
172 .5
GBP
|
— | — | — | — | — | — | — | — |
| Current assets | — | — | — |
884,200,000
GBP
|
— | — | — | — | — |
909,400,000
GBP
|
— | — | — | — | — | — | — | — |
| Assets | — | — | — |
3,509,300,000
GBP
|
— | — | — | — | — |
3,579,200,000
GBP
|
— | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | ||||||||||||||||||
| Equity [abstract] | ||||||||||||||||||
| Issued capital | — | — | — |
15,100,000
GBP
|
— | — | — | — | — |
15,100,000
GBP
|
— | — | — | — | — | — | — | — |
| Share premium | — | — | — |
707,700,000
GBP
|
— | — | — | — | — |
707,700,000
GBP
|
— | — | — | — | — | — | — | — |
| Other reserves | — | — | — |
1,559,700,000
GBP
|
— | — | — | — | — |
1,629,700,000
GBP
|
— | — | — | — | — | — | — | — |
| Equity attributable to owners of parent | — | — | — |
2,282,500,000
GBP
|
— | — | — | — | — |
2,35 2.5
GBP
|
— | — | — | — | — | — | — | — |
| Non-controlling interests | — | — | — |
14,400,000
GBP
|
— | — | — | — | — |
15,600,000
GBP
|
— | — | — | — | — | — | — | — |
| Equity |
1,660,100,000
GBP
|
707,700,000
GBP
|
100,400,000
GBP
|
2,296,900,000
GBP
|
15,100,000
GBP
|
14,400,000
GBP
|
707,700,000
GBP
|
15,100,000
GBP
|
1, 64 0.0
GBP
|
2, 36 8.1
GBP
|
10,300,000
GBP
|
15,600,000
GBP
|
2,431,100,000
GBP
|
707,700,000
GBP
|
1,645,700,000
GBP
|
15,500,000
GBP
|
15,100,000
GBP
|
47,100,000
GBP
|
| Liabilities [abstract] | ||||||||||||||||||
| Non-current liabilities [abstract] | ||||||||||||||||||
| Non-current provisions [abstract] | ||||||||||||||||||
| Non-current provisions | — | — | — |
17,300,000
GBP
|
— | — | — | — | — |
10,500,000
GBP
|
— | — | — | — | — | — | — | — |
| Deferred tax liabilities | — | — | — |
180,900,000
GBP
|
— | — | — | — | — |
1 92 .8
GBP
|
— | — | — | — | — | — | — | — |
| Non-current liabilities | — | — | — |
875,900,000
GBP
|
— | — | — | — | — |
890,900,000
GBP
|
— | — | — | — | — | — | — | — |
| Current liabilities [abstract] | ||||||||||||||||||
| Current provisions [abstract] | ||||||||||||||||||
| Current provisions | — | — | — |
6,500,000
GBP
|
— | — | — | — | — |
8,600,000
GBP
|
— | — | — | — | — | — | — | — |
| Trade and other current payables | — | — | — |
274,000,000
GBP
|
— | — | — | — | — |
252,000,000
GBP
|
— | — | — | — | — | — | — | — |
| Current liabilities | — | — | — |
336,500,000
GBP
|
— | — | — | — | — |
320. 2
GBP
|
— | — | — | — | — | — | — | — |