.

Looking dead-eyed and disorientated, the pop babe lost it during a shambolic video shoot and ended up "sobbing hysterically".

At one point sad Britney, 25, squatted in her torn fishnets, clutched her Yorkie puppy and stared vacantly into space.

Members of her 100-strong crew were sent home after 18 hours on the shoot, paid for by Britney to promote single Give Me More.

Our pictures were taken in LA on Wednesday, just hours after her disastrous interview with OK! magazine, when her puppy pooped on a £3,248 dress and she wiped grease on it. Things got worse when Britney went to film the vid.

An onlooker said: "She was completely uncooperative and left everyone hanging about when she went for an hour's massage twice.

"She just didn't want to cooperate and was snotty and rude to everyone behaving like a complete and utter spoilt brat.

"When she wasn't p*****g people off, Britney was smoking like a chimney.

"She didn't eat or drink anything other than can after can of Red Bull. She could have drank 20 of them all told.'

And the wheels fell off completely when Britney attempted her raunchy pole dance scene.

The source added: "She had a problem with the extras being about when she did the pole dance.

"She was shy or embarrassed or something and she really started struggling with the whole thing.

"You could see she was getting a bit wobbly but no one expected her to throw a complete fit.

"Suddenly she was in floods of tears and stormed off set. She eventually came back but was sobbing hysterically.

"All her make-up had run. By now it was nearly midnight and the director just called things to an end and sent people home.

"It was a total shambles."

"She is a mess. Britney's out of control and acting like a spoilt brat. It was embarrassing.

"She needs help fast."

Britney, facing a custody battle with estranged husband Kevin Federline for their two children Sean Preston, 22 months, and 10-month-old Jayden James, wants to relaunch her career after shaving her head and going into rehab.

But yesterday there was more trouble. Cops charged her bodyguard Julio Camera with battery after a "scuffle" with photographers.

Britney loses it -