Nigel,

I realise that it doesn't scan too well but I think it was written that way deliberately especially the chorus endings.

350 billion. Maybe a typo or a deliberate exaggeration to further expose the ridiculousness of "the lie"? I don't know but I'm sure the author is well enough informed to know the exact figure.

"Remainers may think this is a great song"   "highly biased against Brexit."

That's most reasonably minded people whom I know, actually.
:-)