However, according to TheWrap, the plan has been put on hold if not dumped entirely. Clarkson's representative denied the pop singer's participation late last month, while Lambert reportedly has yet to be formally approached.
In addition to Fox recently hiring Swedish Idol producer Per Blankens, a European television producer, to replace Nigel Lythgoe and Ken Warwick as one of American Idol's new executive producers, the show's 19 Entertainment production company is also reportedly close to signing deals with producers Jesse Ignjatovic and Evan Prager.
The producing pair have previously worked for MTV and VH1 and also produced a couple of music award shows.
It remains unclear whether Urban, who has publicly expressed his desire to return for another Idol season, will be invited to come back.
In early May, Fox had confirmed prior reports that the network was considering a drastic shakeup that could replace American Idol's entire judging panel for the show's next season in an attempt to boost its steady-declining ratings.