Leases - Movement in lease liabilities (Details) - GBP (£) £ in Thousands	6 Months Ended
Dec. 31, 2023	Jun. 30, 2023	Dec. 31, 2022
Leases
Beginning balance	£ 8,880	£ 3,279	£ 4,430
Cash flows	(806)	(627)	(1,515)
Additions	143	6,084	300
Accretion expense	348	144	64
Ending balance	£ 8,565	£ 8,880	£ 3,279

The amount of liabilities related to the entity's leases. Lease is a contract, or part of a contract, that conveys the right to use an underlying asset for a period of time in exchange for consideration.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 16
-IssueDate 2022-03-24
-Paragraph 47
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2022-en-r&anchor=para_47_b&doctype=Standard
-URIDate 2022-03-24

Name:	ifrs-full_LeaseLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant