Why is the new U.K. Government so concerned with protecting War Criminals?

No, because the Palestinians were abusing the law in this case. The alleged "war criminal" was not guilty of a war crime other than doing something the terrorist wing of the Palestinian Authority didn't like. What HM Government want to do is rein in leftist judges who might be inclined to abuse their authority in order to make points with the global radical left. And you know it.