Full Marks For Charlie
This song dates to 1970-72, and Leon's work with Inter-Action. It doesn't appear to have been conceived as a children's number, however; when it was eventually recorded for Bringing The News From Nowhere (1986), it was found to concern Karl Marx, or more generally, the disarray of the Marxist movement, whom Leon mercilessly lampoons.
"[A] tongue-in-cheek tribute to Karl Marx" - LR (Where Are The Barricades? (sleevenotes), 2016)
Version 1 (1986) With the "Gateway chorus of assorted lefties"