Waving to the crowds from a chopper might increase his cool factor but Pope Francis is sticking with his Popemobile for now as he puts his Harley-Davidson up for auction.

The bike will be sold by Bonhams in Paris tomorrow and is expected to fetch up to £18,000.

But auctioneers say that price is just an estimate and it could end up going for much higher.

Pope Francis blesses 800 bikers in Rome in 2013. Credit: Reuters

In 2013, a Harley-Davidson 1,585CC FXDC Dyna Super Glide Custom, which also belonged to Pope Francis, sold for nearly £200,000 - making it the 19th most valuable motorbike ever sold.

That same year, the Pope blessed a group of bikers in St. Peter's Square in Rome.

All proceeds from the sale of the bike will go to charity.