Statement Of Financial Position [Abstract]
| Concept |
As at 2022-10-01 |
As at 2022-10-01 |
As at 2022-10-01 |
As at 2022-10-01 |
As at 2022-10-01 |
As at 2022-10-01 |
As at 2022-10-01 |
As at 2022-10-01 |
As at 2021-10-02 |
As at 2021-10-02 |
As at 2021-10-02 |
As at 2021-10-02 |
As at 2021-10-02 |
As at 2021-10-02 |
As at 2021-10-02 |
As at 2021-10-02 |
As at 2021-10-02 |
As at 2020-10-03 |
As at 2020-10-03 |
As at 2020-10-03 |
As at 2020-10-03 |
As at 2020-10-03 |
As at 2020-10-03 |
As at 2020-10-03 |
As at 2020-10-03 |
As at 2020-10-03 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | ||||||||||||||||||||||||||
| Assets [abstract] | ||||||||||||||||||||||||||
| Non-current assets [abstract] | ||||||||||||||||||||||||||
| Property, plant and equipment | — | — | — | — | — | — | — |
2,111,000,000
GBP
|
— | — |
1,984,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Deferred tax assets | — | — | — | — | — | — | — |
–
GBP
|
— | — |
47,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Non-current assets | — | — | — | — | — | — | — |
2,441,200,000
GBP
|
— | — |
2,361,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Current assets [abstract] | ||||||||||||||||||||||||||
| Current inventories | — | — | — | — | — | — | — |
12,600,000
GBP
|
— | — |
12,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Trade and other current receivables | — | — | — | — | — | — | — |
30,100,000
GBP
|
— | — |
52,300,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Cash and cash equivalents | — | — | — | — | — | — | — |
27,700,000
GBP
|
— | — |
32,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Current assets other than non-current assets or disposal groups classified as held for sale or as held for distribution to owners | — | — | — | — | — | — | — |
76,700,000
GBP
|
— | — |
101,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Current assets | — | — | — | — | — | — | — |
81,500,000
GBP
|
— | — |
106,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | ||||||||||||||||||||||||||
| Equity [abstract] | ||||||||||||||||||||||||||
| Issued capital | — | — | — | — | — | — | — |
48,700,000
GBP
|
— | — |
48,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Retained earnings | — | — | — | — | — | — | — |
3,100,000
GBP
|
— | — |
151,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Share premium | — | — | — | — | — | — | — |
334,000,000
GBP
|
— | — |
334,000,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Treasury shares | — | — | — | — | — | — | — |
110,900,000
GBP
|
— | — |
111,100,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Equity |
417,100,000
GBP
|
50,700,000
GBP
|
6,800,000
GBP
|
334,000,000
GBP
|
48,700,000
GBP
|
110,900,000
GBP
|
3,100,000
GBP
|
648,100,000
GBP
|
–
GBP
|
48,700,000
GBP
|
406,400,000
GBP
|
111,100,000
GBP
|
81,400,000
GBP
|
151,100,000
GBP
|
334,000,000
GBP
|
6,800,000
GBP
|
360,500,000
GBP
|
111,900,000
GBP
|
108,700,000
GBP
|
248,900,000
GBP
|
374,300,000
GBP
|
430,600,000
GBP
|
334,000,000
GBP
|
6,800,000
GBP
|
23,700,000
GBP
|
48,700,000
GBP
|
| Liabilities [abstract] | ||||||||||||||||||||||||||
| Non-current liabilities [abstract] | ||||||||||||||||||||||||||
| Non-current provisions [abstract] | ||||||||||||||||||||||||||
| Non-current provisions | — | — | — | — | — | — | — |
3,300,000
GBP
|
— | — |
9,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Deferred tax liabilities | — | — | — | — | — | — | — |
8,000,000
GBP
|
— | — |
–
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Non-current liabilities | — | — | — | — | — | — | — |
1,603,900,000
GBP
|
— | — |
1,771,800,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Current liabilities [abstract] | ||||||||||||||||||||||||||
| Current provisions [abstract] | ||||||||||||||||||||||||||
| Current provisions | — | — | — | — | — | — | — |
1,000,000
GBP
|
— | — |
1,500,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Trade and other current payables | — | — | — | — | — | — | — |
204,400,000
GBP
|
— | — |
220,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Current liabilities | — | — | — | — | — | — | — |
270,700,000
GBP
|
— | — |
289,700,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — |