The ID card trials, allegedly with 10000 volunteers, have demonstrated that the technology is unreliable. Ministers are unconcerned about this, however, because the trials were apparently about finding out about people's attitudes towards the scheme.
These are the trials which were supposed to be comprehensive, which would last 6 months and not be compromised but early problems with the technology delayed the start date for three months; then the government refused to push back the end date, then they could not get enough volunteers...
Now they don't care if the technology is useless. It's ok to spend billions on it as long as they can kid people into feeling "comfortable" about it.
I must be living in a parallel universe, where the consultants' (Atos Origin) report is all very upbeat (well that's what the government paid them for), whilst providing damning evidence which in a world grounded in reality would commit the scheme to oblivion.