Earlier today, it was announced that the PWL reunion gig had been abandoned after the Hyde Park festival site was deemed unsafe due to its water-logged and muddy state.
Donovan and Kylie Minogue were set to reunite on stage to sing their 1988 hit 'Especially For You' for the first time.
Announcing the news on Twitter, the singer said: "Everyone who was heading to Hyde Park tomorrow ..... What can I say .... we are all extremely disappointed.
"We appreciate that you all must be extremely frustrated but please bear in mind that this decision was not taken Lightly.
"Can't believe it .... Was really looking forward to celebrating the wonderful work of Mike Matt and Pete and all who made those songs. So special to a generation!"
The Superstar judge, who signed up for the 25th anniversary concert in March alongside other Stock Aitken Waterman acts, was pictured rehearsing with Minogue yesterday.
The 44-year-old added: "Yesterday was a great rehearsal .... Band,Songs and even my voice was all sounding great Kylie and I were really looking forward too singing 'Especially For You' for the first time LIVE."
However, Donovan hinted that the former Neighbours stars will eventually perform the song together, adding: "Well... you never know, I'm sure we'll get another chance !! Fingers crossed."
Watch the video for Kylie and Jason's 'Especially for You' below: