She is already preparing for what is being labelled one of the biggest comebacks in pop.

But now Britney Spears is beginning an even bigger fight - to regain custody of her two young sons.

The star, who recently lost custody of sons Sean Preston, 2 and Jayden James, 1, to ex-husband Kevin Federline  has made no secret of the fact that she wants to regain custody of her boys.

Britney arrives at celebrity lawyer Barry Tarlow's office as she prepares to launch a new fight for greater access to her sons

Britney, accompanied by mother Lynn, visited celebrity lawyer Barry Tarlow's office yesterday, fuelling speculation she is fighting to regain full custody of the toddlers.

Britney has already revealed she is preparing for a comeback in the next six to nine months and wants her young sons back by her side.

The singer has been in  fine form of late and is looking better than ever after bouncing back from recent health troubles.

The former Princess of Pop has also been happier after agreeing to the settlement Federline.

As part of the agreement, Britney is allowed two visits and one overnight stay with her two sons, while her ex-husband retains primary custody.

But the mother-of-two is now hoping the custody arrangement will be altered  so she can spend even more time with her boys and eventually retain full custody.

Britney arrives at the office of her lawyer, while mother Lynn keeps a watchful eye on the media

A hearing has already been set for September 16 and while cost hasn't appeared to be a major issue so far, the custody battle could leave her with more than £350,000 in legal bills.

Her battle to establish access rights to Sean Preston and Jayden James, led to two law firms billing her a combined total of £230,000, court documents have revealed.

Britney, 26, also agreed to pay Kevin's legal fees, which amounted to around £120,000.

But despite her recent troubles, Spears remains upbeat and reveals she has been busy experimenting with a new image and style in preparation for her career comeback.

'It is more urban. I'm working with producers who are just amazing.There is a fresh new energy,' she told OK magazine.

'The image factor is a little older too. The videos will be very different.'