Green’s Dictionary of Slang

Normandy Beach n.

[rhy. sl.; ult. ref. to D-Day and the Normandy landings on 6 June 1944]

a speech.

1985		Wheeler & Broadhead Upper Class Rhy. Sl. 35: They listen gloomily to the Queen’s Normandy beach.
1998		R. Puxley Fresh Rabbit.