If a person is able to get away with the issue of photographic identification, one assumes that the polling staff would be able to make a careful check. However, people were able to walk into the Ministry of Defence, during my time as a special adviser there, with a Crystal Palace supporter's card rather than the necessary identification. Therefore, occasions when people may use incorrect identification to get into places where they should not show that polling staff, who may be under great pressure with a large queue of people outside, may not be able to hold the card up to the light and ensure that the voter is the person shown on the card. Of course, once that test is gone, it is gone. It cannot be brought back and checked later. That would be the benefit of a signature test.