McCarthy grew up in Islington, London and attended Holloway County School, he then worked in a gents outfitter where he was a representative of the Usdaw trade union which sponsored him to study for a diploma at Ruskin College, Oxford.
McCarthy grew up in Islington, London and attended Holloway County School. He then worked in a gentlemen's outfitter, where he was a representative of the Usdaw trade union which sponsored him to study for a diploma at Ruskin College, Oxford.