v3.25.2
Financial liabilities at fair value through profit and loss - Additional Information (Details) - Convertible senior secured notes
$ / shares in Units, £ in Thousands
12 Months Ended
Dec. 15, 2021
USD ($)
shares
Dec. 31, 2024
USD ($)
$ / shares
shares
Jun. 30, 2025
USD ($)
shares
Jun. 30, 2025
GBP (£)
shares
Dec. 23, 2024
USD ($)
$ / shares
shares
Financial liabilities at fair value through profit and loss          
Convertible shares | shares 1,818,182        
Ordinary shares | shares   47,343,585      
Market value per share | $ / shares   $ 7.42      
Covenant for retention of cash under contract     $ 10,000,000    
Cash at bank held to satisfy covenant under contract | £       £ 7,298  
Mudrick capital          
Financial liabilities at fair value through profit and loss          
Principal amount $ 200,000,000        
Aggregate purchase price $ 192,000,000        
Conversion rate | shares 9.09091        
Convertible senior secured notes principal amount, per instrument $ 1,000        
Interest paid in cash | Mudrick capital          
Financial liabilities at fair value through profit and loss          
Interest rate         10.00%
Interest paid in-kind and semi-annually in arrears          
Financial liabilities at fair value through profit and loss          
Interest rate 9.00%        
Interest paid in-kind and semi-annually in arrears | Mudrick capital          
Financial liabilities at fair value through profit and loss          
Interest rate         12.00%
First half of principal amount          
Financial liabilities at fair value through profit and loss          
Conversion price (Per share price) | $ / shares   $ 2.75      
Original Debt, Amount   $ 130,000,000      
Mudrick capital | First half of principal amount          
Financial liabilities at fair value through profit and loss          
Conversion rate | shares         363.636
Convertible senior secured notes principal amount, per instrument         $ 1,000
Conversion price (Per share price) | $ / shares         $ 2.75
Mudrick capital | Remaining half of principal amount          
Financial liabilities at fair value through profit and loss          
Conversion rate | shares         285.714
Convertible senior secured notes principal amount, per instrument         $ 1,000
Conversion price (Per share price) | $ / shares         $ 3.5
Convertible instruments          
Financial liabilities at fair value through profit and loss          
Convertible shares | shares     39,430,443 39,430,443