Terrorism Bill

In common with my hon. Friend the Member for South Staffordshire (Sir Patrick Cormack), I always listen to my right hon. Friend the Member for East Hampshire (Mr. Mates) with respect on such subjects. My right hon. Friend said that the Government have not made their case and then went on to say, with a degree of certainty in his tone, that 28 days was patently inadequate, so will he be good enough to enlighten the House as to why? It is not at all clear to me how he knows that 28 days is inadequate.