Diana Ross 'singing at Evan and Ashlee's wedding'

Diana Ross is supposedly performing the day her son Evan marries Ashlee Simpson.

The music icon is mother to the 25-year-old Hunger Games actor, who became engaged to Ashlee in January.

And according to E! News, The Supremes singer will grace the stage during their forthcoming nuptial ceremony.

Apparently Diana's daughter Rhonda Ross Kendrick is set to serenade her brother Evan as well, as she is rumoured to be singing alongside her mom during the future performance.

The outlet reports several huge stars have been invited to the affair, including Smokey Robinson and Stevie Wonder amongst others.

The couple are said to be tying the knot closer to the end of summer, on August 31.

Evan has previously spoken about how hands-on his mother Diana has been throughout the wedding planning process.

"She's involved in all levels of my life," he explained to the outlet at SXSW. "She's one of the most incredible mothers ever. My mom is 69 and she's going on tour again. She was on tour last year and even going tour, she's involved in every piece of our wedding [and] engagement party."

Evan popped the question six months after he and Ashlee began dating.

And the star says he was compelled to make her his wife almost immediately.

"Honestly, we could go and get married right now, wherever," he said. "We just want to be married. We're in love. I was giving it time only because I wanted to give it time, but I would have asked her a month after I was with her."