UK Borders Bill

I thank the Minister for giving way; he has been generous. As there is a 12-month limit, will he explain why, under clause 3 on enforcement, somebody who assaults an immigration officer is"““liable on summary conviction to…imprisonment for a term not exceeding 51 weeks””?" Does that not mean that people who are questioned or detained by designated immigration officers will have a perfectly good reason to belt them around a bit, knowing that they will not even face deportation if convicted for doing so?