Spears 'threatens to cancel tour over kids'

Britney Spears has reportedly threatened to cancel her forthcoming world tour if her two children cannot come with her.

According to TMZ, the singer has refused to perform if three-year-old Sean Preston and two-year-old Jayden James are not allowed to travel with her.

Spears had reportedly hashed out a draft agreement with ex-husband Kevin Federline which would see the children staying in "bases" close to her tour venues.

The 27-year-old had hoped to set up three "bases" - New Orleans, New Jersey and Los Angeles - where the boys would stay during the US leg of her world tour, allowing her to commute back and forth from performances to spend time with them.

Spears had also offered Federline up to £3,000 a week to accompany the children, plus his own accomodation in each city.

However, lawyers for both Spears and Federline are reportedly angry that they were not consulted about the deal.

The singer is scheduled to kick off her US tour on March 3 in New Orleans. She will play a "mini-residency" at London's O2 arena from June 3.