v3.26.1
Financial instruments - Additional Information (Details)
 12 Months Ended
Dec. 23, 2024
GBP (£)
Dec. 23, 2024
USD ($)
shares
Dec. 16, 2021
USD ($)
shares
Dec. 15, 2021
GBP (£)
Dec. 15, 2021
USD ($)
Dec. 31, 2025
GBP (£)
Dec. 31, 2024
GBP (£)
Dec. 31, 2025
USD ($)
Jan. 24, 2025
$ / shares
Dec. 31, 2024
USD ($)
Dec. 15, 2024
Dec. 31, 2023
GBP (£)
Disclosure of financial liabilities [line items]                        
Total interest expense for financial liabilities not held at fair value through profit or loss           £ 194,000 £ 156,000          
Share Price | $ / shares                 $ 5.6      
Change in fair value from own credit risk             22,293,000          
Convertible senior secured notes                        
Disclosure of financial liabilities [line items]                        
Convertible Senior Secured Notes Principal Amount | $   $ 1,000                    
Principal amount outstanding           £ 108,755,000 103,914,000 $ 146,286,000   $ 130,194,000    
Aggregate purchase price       £ 145,000,000 $ 192,000,000              
Change in fair value from own credit risk             £ 22,293,000          
Percentage of increase in company's own credit spread during the period             11          
Convertible senior secured notes | Credit spread                        
Disclosure of financial liabilities [line items]                        
Percentage of decrease in unobservable input           7.50%   7.50%        
Percentage of increase in unobservable input           7.50%   7.50%        
Increase (decrease) in fair value from reasonably possibly increase in unobservable input           £ (7,000,000)            
Increase (decrease) in fair value from reasonably possibly decrease in unobservable input           £ 7,000,000            
Convertible senior secured notes | Minimum                        
Disclosure of financial liabilities [line items]                        
Term of US Government debt to calculate interest rate, fair value measurement inputs           3 years            
Historical share price volatility period of comparable companies, fair value measurement inputs           3 months            
Convertible senior secured notes | Maximum                        
Disclosure of financial liabilities [line items]                        
Term of US Government debt to calculate interest rate, fair value measurement inputs           5 years            
Historical share price volatility period of comparable companies, fair value measurement inputs           4 years            
Convertible senior secured notes | Interest paid in-kind and semi-annually in arrears                        
Disclosure of financial liabilities [line items]                        
Interest rate                     12.00%  
Convertible senior secured notes | Interest paid in cash                        
Disclosure of financial liabilities [line items]                        
Interest rate                     10.00%  
Convertible senior secured notes | First half of principal amount                        
Disclosure of financial liabilities [line items]                        
Conversion rate | shares   363.636                    
Principal amount converted £ 103,997,811 $ 130,194,859                    
Convertible senior secured notes | Remaining half of principal amount                        
Disclosure of financial liabilities [line items]                        
Conversion rate | shares   285.714                    
Convertible senior secured notes | Level 3                        
Disclosure of financial liabilities [line items]                        
Carrying Value           £ 188,526,000            
Financial liabilities at fair value through profit and loss category                        
Disclosure of financial liabilities [line items]                        
Carrying Value           188,813,000 £ 524,676,000          
Financial liabilities, at fair value           188,813,000 524,676,000          
Financial liabilities at fair value through profit and loss category | Convertible senior secured notes                        
Disclosure of financial liabilities [line items]                        
Carrying Value           188,526,000 524,242,000          
Financial liabilities, at fair value           188,526,000 524,242,000          
Financial liabilities at fair value through profit and loss category | Convertible senior secured notes | Mudrick                        
Disclosure of financial liabilities [line items]                        
Carrying Value           188,526,000 524,242,000         £ 109,291,000
Convertible senior secured notes                        
Disclosure of financial liabilities [line items]                        
Financial liabilities, at fair value           £ 188,526,000 £ 524,242,000          
Convertible Note [Member]                        
Disclosure of financial liabilities [line items]                        
Maturity term     five-year                  
Conversion rate | shares     90.9091                  
Convertible Senior Secured Notes Principal Amount | $     $ 1,000                  
Convertible Note [Member] | Interest paid in-kind and semi-annually in arrears                        
Disclosure of financial liabilities [line items]                        
Interest rate     9.00%                  
Convertible Note [Member] | Interest paid in cash                        
Disclosure of financial liabilities [line items]                        
Interest rate     7.00%