v3.26.1
Property, plant and equipment (Details) - GBP (£)
£ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
IfrsStatementLineItems [Line Items]      
Balance at beginning £ 324 £ 571  
Balance at ending 91 324 £ 571
Net book value 91 324 571
Gross Carrying Amount [member]      
IfrsStatementLineItems [Line Items]      
Balance at beginning 1,542 2,298 2,462
Additions 2 9 26
Transfer    
Disposals (608) (765) (190)
Balance at ending 936 1,542 2,298
Balance at beginning 1,218 1,727 1,631
Balance at ending 845 1,218 1,727
Net book value 936 1,542 2,298
Accumulated depreciation and amortisation [member]      
IfrsStatementLineItems [Line Items]      
Transfer    
Charge for the year 188 252 280
Disposals (561) (761) (184)
Fixtures and fittings [member]      
IfrsStatementLineItems [Line Items]      
Balance at beginning 20 32  
Balance at ending 4 20 32
Net book value 4 20 32
Fixtures and fittings [member] | Gross Carrying Amount [member]      
IfrsStatementLineItems [Line Items]      
Balance at beginning 63 63 63
Additions
Transfer    
Disposals (28)
Balance at ending 35 63 63
Balance at beginning 43 31 19
Balance at ending 31 43 31
Net book value 35 63 63
Fixtures and fittings [member] | Accumulated depreciation and amortisation [member]      
IfrsStatementLineItems [Line Items]      
Transfer    
Charge for the year 11 12 12
Disposals (23)
Leasehold improvements [member]      
IfrsStatementLineItems [Line Items]      
Balance at beginning 16 27  
Balance at ending 5 16 27
Net book value 5 16 27
Leasehold improvements [member] | Gross Carrying Amount [member]      
IfrsStatementLineItems [Line Items]      
Balance at beginning 53 53 53
Additions
Transfer    
Disposals
Balance at ending 53 53 53
Balance at beginning 37 26 15
Balance at ending 48 37 26
Net book value 53 53 53
Leasehold improvements [member] | Accumulated depreciation and amortisation [member]      
IfrsStatementLineItems [Line Items]      
Transfer    
Charge for the year 11 11 11
Disposals
Computer equipment [member]      
IfrsStatementLineItems [Line Items]      
Balance at beginning 5 10  
Balance at ending 3 5 10
Net book value 3 5 10
Computer equipment [member] | Gross Carrying Amount [member]      
IfrsStatementLineItems [Line Items]      
Balance at beginning 25 50 88
Additions 2
Transfer    
Disposals (5) (25) (38)
Balance at ending 22 25 50
Balance at beginning 20 40 71
Balance at ending 19 20 40
Net book value 22 25 50
Computer equipment [member] | Accumulated depreciation and amortisation [member]      
IfrsStatementLineItems [Line Items]      
Transfer    
Charge for the year 4 5 7
Disposals (5) (25) (38)
Laboratory equipment [member]      
IfrsStatementLineItems [Line Items]      
Balance at beginning 68 152  
Balance at ending 68 152
Net book value 68 152
Laboratory equipment [member] | Gross Carrying Amount [member]      
IfrsStatementLineItems [Line Items]      
Balance at beginning 680 1,411 1,434
Additions 9 26
Transfer     103
Disposals (575) (740) (152)
Balance at ending 105 680 1,411
Balance at beginning 612 1,259 1,189
Balance at ending 105 612 1,259
Net book value 105 680 1,411
Laboratory equipment [member] | Accumulated depreciation and amortisation [member]      
IfrsStatementLineItems [Line Items]      
Transfer     103
Charge for the year 26 89 113
Disposals (533) (736) (146)
Right-of-use assets [member]      
IfrsStatementLineItems [Line Items]      
Balance at beginning 215 350  
Balance at ending 79 215 350
Net book value 79 215 350
Right-of-use assets [member] | Gross Carrying Amount [member]      
IfrsStatementLineItems [Line Items]      
Balance at beginning 721 721 824
Additions
Transfer     (103)
Disposals
Balance at ending 721 721 721
Balance at beginning 506 371 337
Balance at ending 642 506 371
Net book value 721 721 721
Right-of-use assets [member] | Accumulated depreciation and amortisation [member]      
IfrsStatementLineItems [Line Items]      
Transfer     (103)
Charge for the year 136 135 137
Disposals