A regicide
Written in 1949. Published 1978 by Les Editions de Minuit. (Story from Le miroir qui revient here.)
Inexpensive "pocket book" edition published by J'ai Lu, 19??.
Not published in the UK as far as I know. However on the back of the John Calder publication of Recollections of the Golden Triangle, it's mentioned a translation of this as well as Glissements progressifs du plaisir is "in preparation". This was in 1984! I've heard nothing about either coming out.