v3.26.1
Property, plant and equipment - Balance (Details) - GBP (£)
£ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Property, plant and equipment    
Balance at the beginning £ 3,078  
Balance at the end 2,394 £ 3,078
Plant and Machinery    
Property, plant and equipment    
Balance at the beginning 255  
Balance at the end 177 255
Leasehold improvements    
Property, plant and equipment    
Balance at the beginning 2,534  
Balance at the end 2,051 2,534
Office equipment    
Property, plant and equipment    
Balance at the beginning 191  
Balance at the end 80 191
Vehicles    
Property, plant and equipment    
Balance at the beginning 98  
Balance at the end 86 98
Cost or valuation    
Property, plant and equipment    
Balance at the beginning 5,776 5,681
Additions 290 428
Transfers 0  
Disposals (176) (333)
Balance at the end 5,890 5,776
Cost or valuation | Plant and Machinery    
Property, plant and equipment    
Balance at the beginning 394 465
Additions 0 4
Transfers 0  
Disposals 0 (75)
Balance at the end 394 394
Cost or valuation | Leasehold improvements    
Property, plant and equipment    
Balance at the beginning 4,187 3,347
Additions 242 401
Transfers 0 578
Disposals 0 (139)
Balance at the end 4,429 4,187
Cost or valuation | Assets under construction    
Property, plant and equipment    
Balance at the beginning   612
Additions 0  
Transfers 0 (612)
Disposals 0  
Cost or valuation | Office equipment    
Property, plant and equipment    
Balance at the beginning 1,075 1,137
Additions 48 23
Transfers 0 34
Disposals (176) (119)
Balance at the end 947 1,075
Cost or valuation | Vehicles    
Property, plant and equipment    
Balance at the beginning 120 120
Additions 0  
Transfers 0  
Disposals 0  
Balance at the end 120 120
Accumulated depreciation    
Property, plant and equipment    
Balance at the beginning (2,698) (1,860)
Charge for the year 965 1,088
Disposals 167 250
Balance at the end (3,496) (2,698)
Accumulated depreciation | Plant and Machinery    
Property, plant and equipment    
Balance at the beginning (139) (69)
Charge for the year 78 93
Disposals   23
Balance at the end (217) (139)
Accumulated depreciation | Leasehold improvements    
Property, plant and equipment    
Balance at the beginning (1,653) (1,059)
Charge for the year 725 706
Disposals   112
Balance at the end (2,378) (1,653)
Accumulated depreciation | Office equipment    
Property, plant and equipment    
Balance at the beginning (884) (722)
Charge for the year 150 277
Disposals 167 115
Balance at the end (867) (884)
Accumulated depreciation | Vehicles    
Property, plant and equipment    
Balance at the beginning (22) (10)
Charge for the year 12 12
Balance at the end £ (34) £ (22)