(NOT) [adverb] [not gradable] - certainly notI'd scarcely have done it if I didn't think it was absolutely necessary.His wife died last week, so it's scarcely surprising that he seems unhappy.He would scarcely have said a thing like that (= I don't believe he did).
SCARCELY
Meaning of SCARCELY in English
Cambridge English vocab. Кембриджский английский словарь. 2012