Well, that remains to be seen! It is widely feared that the proposed form of ID card could be open to forgery, and I'm not sure the government have got a proper solution to this. With identity theft being "Crime of the Moment" right now, this could just as easily make things worse as make them better if the whole thing isn't handled properly.
BTW, this isn't actually the first time an ID card idea has been brought up in peacetime. The Conservatives (who now of course, being in opposition, are against the idea) came up with a very similar scheme during Margaret Thatcher's time in office, but on that occasion nothing came of it.