Oldest negotiating trick in the world - ask for a lot more than you actually expect to get.

If in 28 days they can't come up with enough evidence against someone that they may have done something with which thet can be charged, and held longer, it's a pretty strong indication they haven't done anything much.

"I can't tell you all the facts I know that require that you do what I am asking you to do - but you can trust me..." - well Tony couldn't really expect to get away with that again, even with a bunch of lickspittle MPs.