From S4 E4 (“Masonic Mysteries”) of the ITV detective procedural tv show Inspector Morse, an exchange between Morse and his sergeant, Lewis:
(1) Morse: It’s me he wants, it’s me he’s going to get, or rather, it’s me that’s going to get him…
(2) Lewis: Shouldn’t that be: “It’s I who am going to get him”?
It’s all about pronoun case (Acc me vs. Nom I) in it-clefts: roughly, identifying clauses with
subject it, a main verb BE, a predicative NP, and a relative clause missing an NP (the relative clause can have relativizer ∅, that, or a WH-pronoun like who)
— in these instances, clauses supplying the answer to the questions “Who does he want? Who is he going to get? Who’s going to get him?”
And, this being Britain, it’s also all about social class.