v3.26.1
Financial liabilities at fair value through profit and loss - Convertible Senior Secured Notes (Details)
$ / shares in Units, £ in Thousands
6 Months Ended 12 Months Ended
Jun. 26, 2026
USD ($)
May 27, 2026
USD ($)
May 20, 2026
USD ($)
Dec. 15, 2021
USD ($)
shares
Jun. 30, 2026
GBP (£)
shares
Jun. 30, 2026
USD ($)
Dec. 31, 2024
USD ($)
shares
Jun. 30, 2026
$ / shares
Apr. 20, 2026
USD ($)
Dec. 31, 2025
GBP (£)
Dec. 23, 2024
$ / shares
Financial liabilities at fair value through profit and loss                      
Aggregate purchase price | £         £ 7,719            
Proceeds from issuance of Convertible Senior Secured Notes to related party | £         7,719            
Financial liabilities at fair value through profit and loss category                      
Financial liabilities at fair value through profit and loss                      
Financial liabilities | £         93,444         £ 188,813  
Series A Convertible Preferred Shares                      
Financial liabilities at fair value through profit and loss                      
Maximum value of preferred stock issuable                 $ 250,000,000    
Series A Convertible Preferred Shares | Financial liabilities at fair value through profit and loss category                      
Financial liabilities at fair value through profit and loss                      
Financial liabilities | £         1,799            
Convertible Senior Secured Notes                      
Financial liabilities at fair value through profit and loss                      
Aggregate purchase price       $ 192,000,000              
Proceeds from issuance of Convertible Senior Secured Notes to related party       192,000,000              
Convertible Senior Secured Notes | Financial liabilities at fair value through profit and loss category                      
Financial liabilities at fair value through profit and loss                      
Financial liabilities | £         91,271         £ 188,526  
Convertible Senior Secured Notes, additional facility under third supplemental indenture [Member]                      
Financial liabilities at fair value through profit and loss                      
Maximum value of additional convertible notes issuable                 50,000,000    
Convertible Senior Secured Notes, additional facility under third supplemental indenture [Member] | Mudrick capital                      
Financial liabilities at fair value through profit and loss                      
Aggregate purchase price $ 5,000,000   $ 5,000,000                
Maximum value of additional convertible notes issuable                 50,000,000    
Proceeds from issuance of Convertible Senior Secured Notes to related party $ 5,000,000   $ 5,000,000                
Convertible Senior Secured Notes, additional facility under third supplemental indenture, tranche III | Mudrick capital                      
Financial liabilities at fair value through profit and loss                      
Aggregate purchase price   $ 5,000,000                  
Financial liabilities | £         £ 0            
Proceeds from issuance of Convertible Senior Secured Notes to related party   5,000,000                  
Mudrick capital | Convertible Senior Secured Notes                      
Financial liabilities at fair value through profit and loss                      
Principal amount       200,000,000              
Aggregate purchase price       $ 192,000,000              
Convertible shares | shares       1,818,182 47,246,903            
Conversion rate (in shares) | shares       9.09091              
Convertible senior secured notes principal amount, per instrument       $ 1,000              
Ordinary shares | shares             47,343,585        
Cash and cash equivalents | £         £ 7,534            
Proceeds from issuance of Convertible Senior Secured Notes to related party       $ 192,000,000              
Mudrick capital | Convertible Senior Secured Notes, additional facility under third supplemental indenture [Member]                      
Financial liabilities at fair value through profit and loss                      
Aggregate purchase price           $ 10,000,000          
Conversion price (Per share price) | $ / shares               $ 3.5      
Maximum value of additional convertible notes issuable                 50,000,000    
Maximum value of additional convertible notes issuable, per month                 $ 5,000,000    
Proceeds from issuance of Convertible Senior Secured Notes to related party           $ 10,000,000          
Mudrick capital | Convertible Senior Secured Notes, additional facility under third supplemental indenture, tranche III                      
Financial liabilities at fair value through profit and loss                      
Financial liabilities | £         £ 0            
Notice for drawdown of funds given   $ 5,000,000                  
Interest paid in cash | Mudrick capital | Convertible Senior Secured Notes                      
Financial liabilities at fair value through profit and loss                      
Interest rate (in percent)                     10.00%
Interest paid in cash | Mudrick capital | Convertible Senior Secured Notes, additional facility under third supplemental indenture [Member]                      
Financial liabilities at fair value through profit and loss                      
Interest rate (in percent)         10.00%            
First half of principal amount | Mudrick capital | Convertible Senior Secured Notes                      
Financial liabilities at fair value through profit and loss                      
Conversion price (Per share price) | $ / shares                     $ 2.75
Principal amount             $ 130,000,000        
Remaining half of principal amount | Mudrick capital | Convertible Senior Secured Notes                      
Financial liabilities at fair value through profit and loss                      
Conversion price (Per share price) | $ / shares                     $ 3.5
Interest paid in-kind and semi-annually in arrears | Mudrick capital | Convertible Senior Secured Notes                      
Financial liabilities at fair value through profit and loss                      
Interest rate (in percent)       9.00%             12.00%
Interest paid in-kind and semi-annually in arrears | Mudrick capital | Convertible Senior Secured Notes, additional facility under third supplemental indenture [Member]                      
Financial liabilities at fair value through profit and loss                      
Interest rate (in percent)         12.00%