Ashlee Simpson Still Singing

It is believed the duo's unlikely pairing has been masterminded by Fall Out Boy star Pete Wentz who is rumoured to have dated Ashlee and is close friends with Smith.

However, Wentz denies he has anything to do with it, telling Entertainment Weekly: "I doubt I had anything to do with it, because they were friends since she was performing in 'Chicago'. But I definitely only have good things to say about Ashlee - I think the collaboration could be great."
Simpson is also working on tracks with Keane frontman Tim Rice-Oxley, The Neptunes' Chad Hugo and soul singer John Legend on the hotly-anticipated LP.

Ashlee, 22, has recently been romantically linked with Hugo as well as Wentz.

Meanwhile, Ashlee Simpson has given her big sister Jessica's new man her seal of approval.

Jessica, 26, was devastated after the sudden breakdown of her marriage to Nick Lachey in 2005 but recently found love again with musician John Mayer - and Ashlee couldn't be happier for her.

A source told People magazine: "Ashlee loves John. She thinks he is great for her. More importantly, Jess is happy."

Newly-brunette Jessica and John, 29, have been dating for eight months. They confirmed rumours they were an item when they attended Jessica's New Year's Eve party.

A source said of the couple, who have just enjoyed a romantic trip to Rome: "John seems very smitten".