Britney Spears two young sons — Sean Preston and Jayden James — are allowed to join the singer on the European leg of her Circus tour.

The lawyer for Britney’s ex-husband Kevin Federline has said that his client is “more than happy to help facilitate Britney being able to see the boys on the European leg of the tour”.

although Kevin has custody of the boys, Britney “should not have to sacrifice visits with her boys while pursuing her career.

Kevin has even been able to make sure that Britney can maintain the boys’ regular schedule.

Britney Spears has said that she’s as surprised as anyone about the success of her comeback over the last year.

The star hit rock bottom in 2007 with a stay in rehab, repeated hospitalizations and losing custody of her sons but after her dad was appointed to take control of her life, she recovered steadily through 2008. Her comeback singles and album ‘The Circus’, released in December, were huge hits and the accompanying tour has sold out.

She told Hello magazine recently: “A lot of people thought maybe I wouldn’t make it. People thought I was finished, didn’t they?

“I guess for a while last year it looked that way. Nothing I can do about the past. But I’m hoping to prove them wrong now. And I have really put everything I have into this new show.”

But she added that she’s mostly doing it for her sons, three year old Sean Preston and two year old Jayden: “It’s all about history. [I’m] creating history with [my] kids that we can look back on.

“When they’re adults I want my kids to say ‘Mum worked so hard, but she was always there for us’.

“Number one priority for me? My kids. They come first. If the boys are okay, everything else falls into place.”

The boys and their dad Kevin Federline accompanied the star on the recent North American leg of her Circus tour, staying at one of three bases around the US to allow Britney to maintain her access throughout the tour. The UK leg of the tour starts next week, followed by concert dates across Europe.