just on it's own terms, not looking at other effects, a zero tarrif deal would only be about tarrifs. It would have little impact on rules of origins and would require significant red-tape and extra paperwork. SO like much of brexit, it requires a LOT of extra effort, the goodwill of other nations and risk of splitting up the union to achieve very little at all If the deal struck yesterday was the one advertised on buses 3 years ago would it have won? Not even close