Is it a "bill" - or just something the border agency can do with the government saying "do it"?
If it's a bill that has to go through the house, well I wouldn't count on it being passed, I really can't see most of Labour supporting it in it's entirety, and the LibDems possibly even less so.
Can't really imagine the tories imposing a three line whip on such an unimportant matter (to them). The lords are also possible to request changes all delaying it.
Since it's supposed to happen in just over 2 months, then it surely can't be a bill? There just isn't time.