Its a reference to a rather entertaining confrontation between Dowd and Marshall-Andrews several months ago.
Marshall-Andrews was seen talking to Tory MPs at a division where he voted against the government. Dowd went over to remonstrate with M-A who called him "another f****t". Didn't make too much hay in the mainstream press, but a number of blogs picked it up, and my favourite publication - Private Eye.
Apparently he called him the Latin term "Faccio" (meaning someone who does the bidding of others), which is pronounced as in the Cs are Gs. Bob Marshall-Andrews doesn't seem like a homophobe to me but he
does seem the sort who would use Latin insults
