Jermaine Jackson‘s planned Vienna, Austria tribute to his late brother Michael is beginning to look like a case of wishful thinking – Mary J. Blige has turned the show down.

Jackson announced Blige and Chris Brown would be among the headliners at a press conference on Tuesday, but both have since insisted they won’t be part of the September 26 concert at the Imperial Schonbrunn Palace.

Brown’s spokesperson has said, “Chris is not confirmed to perform or participate in any capacity for this show,” and now Blige’s people have followed suit – an aide insists the singer will be in Italy and not in Austria on the day of the tribute.

Natalie Cole, Akon and Sister Sledge are also on the bill, according to Jermaine.

Meanwhile, promoters are trying to play down reports that the King of Pop’s brother is staging the Vienna show against his mother Katherine’s wishes. Event organizer George Kindel says, “She will be there with Michael Jackson’ s kids.”