I think what the hon. Member has asked me to do is put a time limit on this, and I have already said clearly that just does not work. We have a duty to those in the immigration system, but we have a duty to protect the public too. The introduction of a 28-day detention time limit would severely limit our ability to remove those who refuse to leave voluntarily, and would encourage and reward abuse, to answer the question raised by the hon. Member for Sheffield Central, in some cases from individuals who present a genuine threat to the public, which is not the effect I consider the hon. Members intend with new clause 38.