Published Wednesday, 21 August 2013
The musician, real name Benjamin Ballance-Drew, was performing as the opening act for rap superstar Eminem, but he left the stage early after just a handful of songs.
Plan B reportedly raged at the crowd, cursing at them for their lacklustre response to his set.
Reports state the star also called the audience the "tamest f**king crowd of my life," adding: "You should feel ashamed. No f**king mosh pit, not one f**king mosh pit."
He then checked how long he had left to play and retorted: "10 minutes? 10 minutes... Well, we're only gonna play one more song cause we don't really wanna be here," before storming off stage.
The controversy has hit headlines in his native UK, with critics accusing the star of throwing an onstage tantrum, while the story also created a buzz on Twitter.com, with gig-goers and fans wading into the debate over the star's behaviour.
One concert-goer wrote in a post on Twitter.com: "Plan B was such a w****r at Slane," while another added: "Artists should remember who's paying at a gig, and who's being paid. You signed the contract, honour it."
Plan B has yet to respond to the controversy.