Cher has given the strongest indication yet that she will headline the Sydney Mardi Gras 40th anniversary celebrations.

In a tweet this morning, the singer, now 71, all but confirmed she would be in Australia during March.

The festival’s organisers are yet to officially confirm she will perform at the event on 3 March at Sydney’s Hordern Pavilion. But the tweet lends significant weight to persistent rumours that Cher would headline the festival.

There were about 600 tickets left on Friday, but, just three hours after Cher’s tweet, organisers said the event was now sold out.

“We have lots of exciting announcements coming up v soon – it’s going to be an INCREDIBLE NIGHT!,” organisers said on Saturday afternoon.

Cher, an immensely popular gay icon, would be a significant coup for the Mardi Gras in its 40th year. It would also bring her to Australia in the months after same-sex couples begin to marry.

Cher’s last Australian tour was in 2005, and she has never before performed at the event.

Boy George, George Michael, Cyndi Lauper, and Olivia Newton-John are among previous headliners. Lauper, another big name, performed at the Mardi Gras’ 30th anniversary.