If Boris Johnson wanted to call someone weak or cowardly, he'd say "namby-pamby woofter."Calling some a pussy does happen here, but only as a vulgar and regrettable Americanism. You wouldn't substitute another word. Calling someone a fanny is like calling someone a plonker, a pillock or a div.
so Boris might say "do you want to be remembered as a patriot, or remembered as a cunt?"