Britney Spears is threatening to cancel the start of her tour next month if she is not allowed to take her children on the road with her, according to TMZ.

Britney is trying to secure an agreement with ex-husband Kevin Federline to take their two sons -- Sean Preston and Jayden James -- on the road with her and may not go without them if a deal is not reached in the near term.

The singer plans to rent homes in Los Angeles, New Jersey and New Orleans, Louisiana, where her boys can comfortably stay and she will easily commute between them throughout her 33 date tour.

The 27-year-old reportedly offered K-Fed up to $4,000 a week to accompany the boys, plus his own accommodation in each of the three cities. reports, Britney, K-Fed and Jamie worked out the arrangement without the help of any of the lawyers. We're told a week ago K-Fed's lawyers became aware of the plan and were furious, thinking Jamie went behind their backs.