Grumpy The Fall star Mark E. Smith once demanded silence from Mumford & Sons when they started partying backstage at an Irish music festival.

The folk rockers were celebrating reaching number one in the U.K. charts with their first album two years ago when Smith found himself in a trailer next to them at an event in Dublin.

He tells The List, "I was talking to the promoter who's a mate of mine and said, 'Look, don't take the p**s, you've stuck us next to some mongoloid Irish folk band'.

"The promoter turns around and says, 'They're number one in your English charts'. I thought he was f**king joking. They started clopping about singing, (they) sounded like they were dancing on the tables - so I told them to shut the f**k up."