I suspect that this might be a tactic intended for the domestic audience. The current government is extremely unlikely to be in power a week from now, and might be doing this just to force the next government to either follow through or retract it

How can the Oslo accords be used as an argument against Israeli prosecution if Israel has done exactly nothing to uphold them? What in the dystopian fuck is this?

The ICC arrest warrants were never going to deter anyone from doing anything, so the UKs stalling tactic is therefore irrelevant to saving lives. In fact, it gives the court a chance to strengthen its jurisdiction. Not worried about this.