Well, up to a point, more of a paraphrase and they were quoting a propaganda poster from the Spanish civil war era.
Actually, I grew up in a house where yodelling was to be heard emanating from the gramophone, my parents owned a Frank Ifield album that featured it, so I’m a little less sensitive to it and, like @Frank Blank, I find it quite amusing in Focus tunes, a bit of whimsy in otherwise quite ‘serious’ music.