Green’s Dictionary of Slang

a rich and powerful person.

2000		J.J. Connolly Layer Cake 166: Everyone’s a grass, a slag [...] or thinks they’re Charlie Potatoes cos they’ve got a few bob. [Ibid.] 206: These fuckers don’t give a fuck if you are a big Charlie-new-potatoes gangster in London.
2002		J. Cameron Hell on Hoe Street 48: Bit of a f . . . bit of a goer was Kamran. Charlie Big Potatoes innit?