Kevin Federline, the estranged husband of Britney Spears, has revealed that he was "completely blindsided" when the pop star decided to file for divorce.

The aspiring rapper split from the singer in 2006 and Spears endured a public meltdown while the pair battled for custody of their two young sons.

However, Federline has now revealed that it was Spears' idea to split.

He also said that all he has ever cared about is the welfare of his children and is not interested in his ex-wife's fortune.

"I told [my lawyer] that I would spend every last dime that I had to make sure that my children are okay. That's all that mattered. I didn't know how much power Britney had. That really scared me," Federline told People magazine.

Despite the couple's bitter struggle, Federline insists that he supports Spears in the recovery of both her personal and professional life.

"That's the mother of my children. There's nothing more that I want than for her to be in the best health and doing what she loves to do," he said.

Spears recently released her new album Circus.