Annual report pursuant to Section 13 and 15(d)

Share based compensation - Option Activity (Details)

v3.19.3.a.u2
Share based compensation - Option Activity (Details) - GBP (£)
£ / shares in Units, £ in Thousands
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Options    
Exercised (in shares) (3,549,298) (5,334,936)
Stock options    
Options    
Outstanding at the beginning of the period (in shares) 87,564,719  
Granted (in shares) 23,699,793  
Exercised (in shares) (3,549,298)  
Forfeited (in shares) (18,837,142)  
Outstanding at the end of the period (in shares) 88,878,072 87,564,719
Weighted Average Exercise Price Per Option    
Outstanding at the beginning of the period (in dollars per share) £ 0.60  
Granted (in dollars per share) 0.41  
Exercise price (in dollars per share) 0.08  
Forfeited (in dollars per share) 0.60  
Outstanding at the end of the period (in dollars per share) £ 0.57 £ 0.60
Additional disclosures    
Outstanding - Average Remaining Contractual Term (Years) 6 years 9 months 18 days  
Outstanding - Aggregate Intrinsic Value £ 1,991  
Exercisable - Options 51,953,196  
Exercisable - Weighted Average Exercise Price Per Option £ 0.63  
Exercisable - Average Remaining Contractual Term (Years) 5 years 7 months 6 days  
Exercisable - Aggregate Intrinsic Value £ 263  
Options granted on market value at grant date    
Options    
Outstanding at the beginning of the period (in shares) 79,465,357  
Granted (in shares) 15,679,383 20,771,970
Exercised (in shares) (2,406,298)  
Forfeited (in shares) (16,092,106)  
Outstanding at the end of the period (in shares) 76,646,336 79,465,357
Weighted Average Exercise Price Per Option    
Outstanding at the beginning of the period (in dollars per share) £ 0.66  
Granted (in dollars per share) 0.62  
Exercise price (in dollars per share) 0.12  
Forfeited (in dollars per share) 0.70  
Outstanding at the end of the period (in dollars per share) £ 0.66 £ 0.66
Additional disclosures    
Outstanding - Average Remaining Contractual Term (Years) 6 years 6 months  
Outstanding - Aggregate Intrinsic Value £ 139  
Exercisable - Options 51,137,121  
Exercisable - Weighted Average Exercise Price Per Option £ 0.64  
Exercisable - Average Remaining Contractual Term (Years) 5 years 7 months 6 days  
Exercisable - Aggregate Intrinsic Value £ 139  
Options with nominal exercise price    
Options    
Outstanding at the beginning of the period (in shares) 8,099,362  
Granted (in shares) 8,020,410  
Exercised (in shares) (1,143,000)  
Forfeited (in shares) (2,745,036)  
Outstanding at the end of the period (in shares) 12,231,736 8,099,362
Additional disclosures    
Outstanding - Average Remaining Contractual Term (Years) 8 years 8 months 12 days  
Outstanding - Aggregate Intrinsic Value £ 1,851  
Exercisable - Options 816,075  
Exercisable - Average Remaining Contractual Term (Years) 8 years  
Exercisable - Aggregate Intrinsic Value £ 124