He is urging a clampdown on postal vote fraud by linking it to an ID card scheme. He still hasn't given in has he?
So, let's get this straight. Let's invent a fictional person - this person is totally housebound (for reasons unknown). They register for a postal vote by using a form itself sent by post. They then receive (by post) a postal vote and fill it in. They then sent it back once again by post. At what point will anyone check their ID card and determine whether they are entitled to vote? Or check their biometrics against the central system?
The whole point of postal voting is that it allows people to vote without meeting the returning officer or any other offical - so there is nobody who can spot check ID cards.
Another function for the proposed ID card scheme which actually will have no helpful effect at all.