Britney 'close to breaking point'

Britney Spears is reportedly 'close to breaking point' as she prepares for her first tour since her public breakdown.

The star is becoming increasingly stressed and anxious as pressure grows in the final weeks of rehearsals, according to reports.

"Britney's like a wound-up spring waiting to go off," a source told Now.

"She's still taking medication to get through each day.

"She's so stressed about the kids and so nervous about the tour that it's making her physically ill. The only way she can release that tension is to scream at whoever is closest.

"She locks herself in her room or the bathroom and frequently breaks down in tears."

The 'Circus' singer has allegedly been prescribed Valium and anti-anxiety pill Ativan to supplement her regular bipolar medication.

Spears's live show kicks off in New Orleans on March 3, before playing a "mini-residency" at London's O2 arena from June 3. She recently added a further date in Manchester on June 17.