The amount of the expense relating to short-term leases accounted for applying paragraph 6 of IFRS 16. This expense need not include the expense relating to leases with a lease term of one month or less. Short-term lease is a lease that, at the commencement date, has a lease term of 12 months or less. A lease that contains a purchase option is not a short-term lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 16
-IssueDate 2020-01-01
-Paragraph 53
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2020-en-r&anchor=para_53_c&doctype=Standard
-URIDate 2020-01-01

Name:	ifrs-full_ExpenseRelatingToShorttermLeasesForWhichRecognitionExemptionHasBeenUsed
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Leases, Lease liabilities and expenses related to operating leases (Details) - GBP (£)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Lease liabilities [Abstract]
Lease liabilities	£ 27,233,000	£ 40,250,000
Expenses relating to operating leases	296,000	£ 486,000	£ 4,205,000
Two Terminated Leasehold Properties [Member]
Lease liabilities [Abstract]
Lease liabilities	10,414,000
Four Remeasured Leasehold Properties [Member]
Lease liabilities [Abstract]
Lease liabilities	1,075,000
New Leasehold Property [Member]
Lease liabilities [Abstract]
Lease liabilities	£ 405,000