Ben Wallace writing in The Telegraph about the ID card plan, which he doesn't seem to be against, discusses the proposal of ID under Tony Blair.
Regarding what he describes as a 'fatal flaw in that policy that hopefully Keir Starmer will not repeat':
beyond proving your ID, 'the policy proposed in 2006 established a "live database" that not only stored the nation's IDs, but recorded when they were checked. In other words, it logged an individual's pattern of life which the security services could have access to.'
Not just the security services, anyone who could get permission, or hack their way into the system, could also access the records of who used the ID for checks, when and for what.