Singer Annie Lennox has come out against plans for a civic square over Union Terrace Gardens in her home town of Aberdeen.
Writing on her Myspace blog, the former Eurythmics star turned solo performer urges people to back a campaign to "stop this happening".
The £140m City Square proposals have a promise of £50m in funding from businessman Sir Ian Wood.
However, arts organisation Peacock also has plans for a £13m centre.
The singer wrote: "For me, Union Terrace Gardens was, and still is the green historical heart of the city.
"Like so many towns and cities all over the country, Aberdeen lost a great deal of its architectural heritage and charm through destruction by bulldozer and concrete.
"It made me sad then, and it still makes me sad. I hoped that this kind of 'vandalism' had peaked in the 60's and 70's, but for Aberdeen, it seems to be back with vengeance. What idiocy and madness.
"Aberdeen is your home town. Are you going to sit back, and do nothing while its beautiful historic centre gets ripped out and concreted over? It's down to you to stop this happening."
The plans are currently the focus of a public consultation.
Aberdeen City and Shire Economic Future (Acsef) has said internationally acclaimed architects would be invited to come up with designs for the City Square project if it gets public backing.
The ambitious plan is to raise the centre of Aberdeen
Acsef chairman Tom Smith said: "Given that Ms Lennox appears to have made her comments based on a wholly inaccurate description of the project on Myspace, we are hardly surprised by them.
"Acsef has repeatedly stated that the City Square project aims to create a new civic space and gardens with an iconic arts centre as its centrepiece.
"The claims by objectors that it will be a flat, concrete square similar to Red Square are as misleading as their statement that it will be full of shops and car-parking."
He added: "We will be happy to show Ms Lennox our proposals so she has these facts."
Peacock Visual Arts say the two projects could co-exist.
Approval for its new centre in the gardens has already been given, but the plan is said to be in jeopardy due to the other scheme.
A Peacock spokesperson said: "Annie Lennox is one of Scotland's greatest creative talents.
"We are therefore overwhelmed that she has got involved with the debate on the future of Peacock and Union Terrace Gardens.
"Despite being a major international star Annie's views still seem to reflect her fellow citizens of Aberdeen who are inundating us daily with messages of concern about the future of their gardens and of Peacock and asking what they can do to help save them both."