Tycoon steps in as the future of Aberdeen's historic city centre is put to the vote

Aberdeen city councillors will meet this morning for what has been billed as the most crucial decision to be made by the local authority in half a century.

They will vote on whether to back controversial plans, championed by the oil tycoon Sir Ian Wood, to transform the Victorian gardens into a 140 million City Square or press ahead with rival proposals, already approved, by Peacock Visual Arts for a 13.5m contemporary arts centre at the key site.

Yesterday, as Aberdeen-born rock star Annie Lennox issued another website appeal to councillors to back the Peacock plans, it was revealed that the Stewart Milne Group has approached Aberdeen City Council with a potential third-way solution to the controversy.

ACSEF, the local economic forum which is spearheading the civic square proposals, announced that the construction company had been in contact with the council regarding the potential of Peacock being included in the redevelopment of the Triple Kirks – the Archibald Simpson-designed church complex overlooking the gardens, which has lain derelict for more than 30 years.

But the for a possible compromise was immediately condemned by Peacock, which has only until next month to take up the offer of a 4.3m grant from the Scottish Arts Council to press ahead with its plans for a new contemporary arts centre, designed the by award-winning architects Brisac Gonzalez.

Elly Rothnie, the campaign director for Peacock, declared: "This just muddies the waters for what is a very important council decision tomorrow. The SAC has made it clear that the funding is only attached to the Brisac Gonzalez scheme for the gardens."

She added: "When we were first looking at the city centre we had appraisals on two sites – Union Terrace Gardens and the Triple Kirks – and we couldn't make the Triple Kirks work because it came in at 35m.

"We dismissed it (Triple Kirks] out of hand two years ago. I am quite cross that it is being pulled out of the bag at this point in time."

Tom Smith, the chairman of ACSEF, said: "The best solution for all, we believe, is an iconic contemporary arts centre within the City Square project, but if that is not acceptable to Peacock, then the Triple Kirks site could provide an attractive alternative for them, given that it was their first and preferred choice of location a few years ago. It is within the city's cultural quarter and, with Stewart Milne Group leading the redevelopment, could be cost-effective for them and their public funders."

Lennox, meanwhile, yesterday posted a final message on the debate on her website.

She says: "The Sixties brought about a swathe of architectural vandalism in the name of 'modernity', when part of the core of the city was simply knocked down, to be replaced with a mediocre shopping centre.

"Personally, I can hardly bear to think of a repeat performance, 40 years later."

She adds: "Councillors – the future is in your hands. I earnestly hope you won't make the same mistake again."