v3.26.1
Non adjusting events after the reporting period (Details)
$ / shares in Units, £ in Thousands, $ in Thousands
 6 Months Ended
Aug. 10, 2026
USD ($)
$ / shares
shares
Aug. 05, 2026
USD ($)
$ / shares
shares
Apr. 20, 2026
$ / shares
shares
Dec. 15, 2021
USD ($)
Jun. 30, 2026
GBP (£)
Aug. 12, 2026
GBP (£)
Aug. 12, 2026
USD ($)
Aug. 04, 2026
$ / shares
Disclosure Of Non adjusting Events After Reporting Period [Line Items]                
Aggregate purchase price | £         £ 7,719      
Proceeds from issue of preference shares | £         £ 17,746      
Ordinary share transactions | Registered direct offering                
Disclosure Of Non adjusting Events After Reporting Period [Line Items]                
Issuance of units 33,333,334              
Number of shares per unit 1              
Price per unit | $ / shares $ 1.05              
Ordinary share transactions | Registered direct offering | Tranche C Warrant                
Disclosure Of Non adjusting Events After Reporting Period [Line Items]                
Number of warrant per unit 1              
Number of shares callable by each warrant 1              
Convertible Senior Secured Notes                
Disclosure Of Non adjusting Events After Reporting Period [Line Items]                
Aggregate purchase price | $       $ 192,000        
Convertible Senior Secured Notes | Mudrick Capital and Yorkville | Amendments to the Convertible Note Purchase Agreement                
Disclosure Of Non adjusting Events After Reporting Period [Line Items]                
Conversion price (Per share price) | $ / shares   $ 1.3           $ 3.5
Undrawn borrowing facilities | $   $ 35,000            
Convertible Senior Secured Notes | Mudrick capital                
Disclosure Of Non adjusting Events After Reporting Period [Line Items]                
Principal amount | $       200,000        
Aggregate purchase price | $       $ 192,000        
Convertible Senior Secured Notes | Mudrick capital | Amendments to the Convertible Note Purchase Agreement                
Disclosure Of Non adjusting Events After Reporting Period [Line Items]                
Undrawn borrowing facilities           £ 26,000 $ 35,000  
Series A Convertible Preferred Shares | Mudrick Capital and Yorkville | Amendments to the Convertible Note Purchase Agreement                
Disclosure Of Non adjusting Events After Reporting Period [Line Items]                
Number of ordinary shares established as new management option pool   2,767,806            
Repriced strike rate of share options as part of amendment to convertible note purchase agreement | $ / shares   $ 1.3            
Series A Convertible Preferred Shares | Mudrick Capital and Yorkville | Amendments to the Convertible Note Purchase Agreement | Securities Purchase Agreement                
Disclosure Of Non adjusting Events After Reporting Period [Line Items]                
Value of convertible preferred stock to be issued as part of amendment to convertible note purchase agreement | $   $ 25,000            
Series A Convertible Preferred Shares | YA II PN, Ltd. ("Yorkville") | Securities Purchase Agreement                
Disclosure Of Non adjusting Events After Reporting Period [Line Items]                
Shares issued during the period     25,000          
Purchase price | $ / shares     $ 960          
Series A Convertible Preferred Shares | YA II PN, Ltd. ("Yorkville") | Preferred share transactions | Securities Purchase Agreement                
Disclosure Of Non adjusting Events After Reporting Period [Line Items]                
Shares issued during the period 25,000              
Purchase price | $ / shares $ 960              
Proceeds from issue of preference shares | $ $ 24,000