Statement Of Cash Flows [Abstract]
| Concept |
As at 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
2021-01-01 to 2021-12-31 |
As at 2020-12-31 |
2020-01-01 to 2020-12-31 |
As at 2019-12-31 |
|---|---|---|---|---|---|---|---|---|---|---|
| Statement of cash flows [abstract] | ||||||||||
| Cash flows from (used in) operating activities [abstract] | ||||||||||
| Profit (loss) | — |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
45,500,000
GBP
|
45,500,000
GBP
|
— | — | — |
| Adjustments to reconcile profit (loss) [abstract] | ||||||||||
| Adjustments for decrease (increase) in inventories | — | — | — | — | — |
200,000
GBP
|
— | — |
1 4.8
GBP
|
— |
| Adjustments for depreciation and amortisation expense | — | — | — | — | — |
1 6.4
GBP
|
— | — |
1 7 .1
GBP
|
— |
| Adjustments for provisions | — | — | — | — | — |
6,400,000
GBP
|
— | — |
1. 7
GBP
|
— |
| Adjustments for share-based payments | — | — | — | — | — |
2,500,000
GBP
|
— | — |
900,000
GBP
|
— |
| Other adjustments for non-cash items | — | — | — | — | — |
–
GBP
|
— | — |
900,000
GBP
|
— |
| Adjustments for losses (gains) on disposal of non-current assets | — | — | — | — | — |
1,500,000
GBP
|
— | — |
–
GBP
|
— |
| Cash flows from (used in) operations | — | — | — | — | — |
80,600,000
GBP
|
— | — |
48,300,000
GBP
|
— |
| Interest paid, classified as operating activities | — | — | — | — | — |
2,800,000
GBP
|
— | — |
2,800,000
GBP
|
— |
| Income taxes paid (refund), classified as operating activities | — | — | — | — | — |
9,600,000
GBP
|
— | — |
5,200,000
GBP
|
— |
| Cash flows from (used in) operating activities | — | — | — | — | — |
68,200,000
GBP
|
— | — |
4 0.3
GBP
|
— |
| Cash flows from (used in) investing activities [abstract] | ||||||||||
| Proceeds from sales of property, plant and equipment, classified as investing activities | — | — | — | — | — |
200,000
GBP
|
— | — |
–
GBP
|
— |
| Purchase of property, plant and equipment, classified as investing activities | — | — | — | — | — |
33,000,000
GBP
|
— | — |
23,500,000
GBP
|
— |
| Purchase of intangible assets, classified as investing activities | — | — | — | — | — |
1,600,000
GBP
|
— | — |
1,400,000
GBP
|
— |
| Cash flows from (used in) investing activities | — | — | — | — | — |
20,000,000
GBP
|
— | — |
24,900,000
GBP
|
— |
| Cash flows from (used in) financing activities [abstract] | ||||||||||
| Proceeds from issuing shares | — | — | — | — | — |
–
GBP
|
— | — |
55,000,000
GBP
|
— |
| Payments to acquire or redeem entity's shares | — | — | — | — | — |
5,000,000
GBP
|
— | — |
1,000,000
GBP
|
— |
| Proceeds from borrowings, classified as financing activities | — | — | — | — | — |
5,000,000
GBP
|
— | — |
80,000,000
GBP
|
— |
| Repayments of borrowings, classified as financing activities | — | — | — | — | — |
20,000,000
GBP
|
— | — |
1 35.0
GBP
|
— |
| Payments of lease liabilities, classified as financing activities | — | — | — | — | — |
5,300,000
GBP
|
— | — |
5,200,000
GBP
|
— |
| Dividends paid, classified as financing activities | — | — | — | — | — |
1 3. 7
GBP
|
— | — |
–
GBP
|
— |
| Cash flows from (used in) financing activities | — | — | — | — | — |
38,200,000
GBP
|
— | — |
1 0.5
GBP
|
— |
| Increase (decrease) in cash and cash equivalents after effect of exchange rate changes | — | — | — | — | — |
1 0.0
GBP
|
— | — |
4,900,000
GBP
|
— |
| Cash and cash equivalents |
41,500,000
GBP
|
— | — | — | — | — | — |
3 1.5
GBP
|
— |
26,600,000
GBP
|