You have a proof for that quote? I don't find any.
I find only this one, called "We shall fight on the Beaches" (Churchill to the House of Commons, 1940):
...We shall go on to the end, we shall fight in France, we shall fight on
the seas and oceans, we shall fight with growing confidence and growing
strength in the air, we shall defend our Island, whatever the cost may
be, we shall fight on the beaches, we shall fight on the landing
grounds, we shall fight in the fields and in the streets, we shall fight
in the hills; we shall never surrender...