It didn't take long did it? OK so we put your "illegals" in tents in a field and save £2bn minus set up costs, staff, security (oh, and the field is at the end of your street) . Where's the rest coming from? Who do you want to see worse off, pensioners, the very poor, the very rich, workers, those out of work, the poorly? Because from what I can see all of those groups are untouchable for various reasons.
What I'm saying is none of this is easy and will impact groups far beyond those that we initally think may/should/could be affected.