Re: What is driving this?
Harmonisation with continental practice. The majority of EU member states have ID cards. We're nearly unique in not having them. It's no surprise that every party that gets a whiff of power supports it - they're taking the advice of their civil servants, and the civil service in turn is following the EU principle of voluntary harmonisation that usually precedes the commencement of discussions for a directive setting a common policy. It's a long and drawn-out process.