The Rolling Stones are "quietly confident" they can persuade Adele to join them for a London show.
The legendary British rockers are performing in Hyde Park next month and want to line up a series of big female stars to join them. Top of their wish list is award-winning singer Adele, who has kept a low-profile since the birth of her son last October.
"The Stones would love to get Adele on with them. It would be a massive coup, even for them, because she's been a bit reclusive since her son Angelo James was born. She is the name they want to announce as their special guest - and their invite should be special enough to get her out on stage," a source told British newspaper The Sun.
"At the minute it's 50/50 that she'll do it, but Mick [Jagger] is quietly confident he can pull it off. They want to make the Hyde Park shows a highlight of their tour, and her appearing would make it really special."
The Rolling Stones are also apparently lining up Lady Gaga and Florence Welch to join them at shows this summer.
They are known for inviting female vocalists on stage during their tour, and most recently performed live with Sheryl Crow in the US.
"The group think female performers are a great complement for Mick ever since Florence Welch got on stage with them at London's O2 Arena last year for Gimme Shelter," the source added.
"Gaga, Paloma and Flo would all do well in the Hyde Park shows, but Adele is the big prize this summer."
Guitarist Ronnie Wood recently revealed he is "pleased" The Rolling Stones are returning to Hyde Park after 44 years because he "never thought" it would happen.
The band will perform at the central London venue where they bid farewell to late guitarist Brian Jones just two days after the musician's 1969 death.
Frontman Mick famously read a poem in tribute and thousands of butterflies were released. Mick recently hinted he may dig out the white gown he wore for the show 44 years ago.
"You never know. I can still get into it. I can still just about get into the zippers. I tend to choose my dresses at the last minute," he said.