Northern Ireland Protocol Bill

I suspect that when the Foreign Secretary was campaigning for Britain to remain in the European Union, she never in a million years thought she would be standing here proposing a Bill of this sort. In light of the comment she just made about article 16, why are the Government not proposing to use the legal method to raise these questions with the European Union through the treaty they signed, rather than claiming necessity? The Foreign Secretary has yet to give me a single example where the British Government have claimed necessity for abrogating a treaty they have negotiated and signed.