Hundreds of thousands of Leave.EU newsletters were sent to Banks' customers.
The five things you need to know about politics today
Leave.EU founder also says he would now vote 'Remain'.
The multi-millionaire was a prominent campaigner for Brexit.
Questions raised over "true circumstances" of funding arrangement.
The Leave.EU found he was joining in anticipation of a leadership battle.
He's called the story 'fake news'.
Seems the best isn't always British