Just wait until May..
I thought that his best chance of avoiding extradition was simply to string things out until May. The conservatives have gone on record as saying that the current extradition arrangement with the US is asymmetric and unfair (and is of course even more lop-sided than it could be until the US legislators get off their backsides and bother to ratify it!). The lack of ratification from the US would be a good excuse to rescind the current "you are not allowed to argue against our case" rules.