The 29-year-old singer is set to kick off her series of shows in California on June 17, but according to The Sun, she has caused chaos by asking to push the date back.
A source told the newspaper, 'Britney has told her management that she wants to delay her concert dates because she's not feeling ready.
'She doesn't feel she has enough time to prepare and has asked management to pull all her dates and postpone everything until later on in the year.
'She's a perfectionist and wants everything to be better than ever before.
'She is having to compete with other huge female stars such as Rihanna and Lady Gaga now so she wants to step the show up.'
The source continued, 'Obviously it's gone down like a lead balloon because venues and staff are booked and ready to go.
'They are trying to talk her round or at least hoping she'll consider going out in September.
'Either way, there are a lot of meetings going on about how to announce it and handle it. It's a massive headache.'
Tickets for the show were due to go on sale on Saturday, but according to the report, this date has now been scrapped.