Fake Banksy on eBay?

This has recently appeared for auction on eBay and Chaos wants to know if it's genuine. Er ... I don't pretend to know, but my guess is they don't speak French where Banksy comes from and I reckon the lettering is too arty-farty for Banksy. And where's the Banksy humour? No, I reckon that bidder prepared to lash out £1 has its mark. Of course the only person who can tell us for sure is the lad himself. Banksy?