Britney Spears' pop comeback has been dealt a blow by the Pussycat Dolls - her cameo in the group's new promo for When I Grow Up has been axed from the final edit.

Spears has filmed a clip for the Pussycat Dolls' music video in which she returns to her natural blonde locks.

Spears filmed the segment in a car in Los Angeles last week, and a source tells Usmagazine.com of her appearance: "They all wave at each other as they are passing in traffic - that is it. Of course, Britney looks hot and blonde.

"It is a very short sequence, but (Spears) had a lot of fun with it. Britney really likes the Dolls' music and when she saw them on the MTV (Movie Awards), she was totally down to do the video."

But the cameo has now been shelved for good for reasons as yet unknown, reports MTV.com.

Representatives for both parties were unavailable for comment as WENN went to press.

- Britney Spears Gallery

(This news article provided by World Entertainment News Network)