Bon Jovi slams Bieber in a recent interview with the UK's Standard.

The 51-year-old rocker says of Bieber "He's an a—hole. Go to f—kin work" after Justin was 2 hours late for a performance at the O2 Arena.

Justin Bieber has had a rough few weeks, and they are just getting worse after the Slippery When Wet rocker spoke to the London Evening Standard in Vienna and claimed Bieber was “alienating fans” with his behavior.

The entire Bon Jovi Bieber slam is about professionalism and not leaving your fans hanging.

“Every generation has guys that do that, none of that is new.

"They run the risk of disrespecting their audience members who have worked hard to pay for their ticket, to give you the permission to take two or three hours of their lives — or in that kid’s case, 80 minutes of their lives.

"Do it once, you can be forgiven. Do it enough times and shame on you.

"They won’t have you back. Then it just becomes a cliché. It’s really not cool — you’re an a**hole. Go to f***in’ work!”

Justin claims after his recent show at London’s O2 Arena, that the reason he was late was because of “technical issues.”

Bieber also claims he was only 40 minutes late.

But fans of the Canadian pop star were left hanging and when he finally did take the stage, he wasn’t enthusiastic about performing.

He actually fainted at the O2 Arena back in March, amid reports he was partying way too much and dehydrated.

The pop star even cried onstage at the O2 Arena in 2011. Justin Bieber does not have the best of luck at the London concert venue.

The 19-year-old pop star was also in the news for the Chris Brown bromance and the Selena Gomez kiss at the Billboard Music awards last Sunday.

Bieber and Gomez got a bit a shade thrown their way by Taylor Swift’s disgusted reaction after embracing backstage.

Bon Jovi, for his part, has his own problems. His guitarist, ex Heather Locklear flame Richie Sambora, may be experiencing alcohol issues, and will likely miss the Barclaycard British Summer Time festival.

Jon Bon Jovi, even threw a dig in against Sambora when he said U2 couldn’t perform without guitarist The Edge, but Sambora’s replacement would be fine and Bon Jovi didn’t need his absent guitarist.

“It’s getting more and more difficult every day to not just sit here and say something... Because all I can say is this — it’s for personal reasons. He’s been through it before, fortunately for us the same guy who filled in last time was available this time.

“Life goes on, so if someone chooses not to be here... unlike if this were, God forbid, The Edge, and he for some reason couldn’t make a U2 show, [then] it would be very difficult to just step in.”

First Bon Jovi slams Justin Bieber then his guitarist, Richie Sambora. Who’s next?