Salt Lake City may tell The Leonardo arrivederci.

Given the museum's shaky fundraising, missed deadlines and busted budgets, Mayor Ralph Becker is ready to consider something other than a science and cultural center at the former main library.

The freshman mayor also is dismissing The Leonardo's latest proposal to construct the three-level interactive science center in phases for half the $50 million original cost. The first phase would be $16 million.

"We don't want to do something that is going to be a patch effort," Becker said Saturday, adding any blueprint for the old library must be sufficiently "green." "What they delivered does not include the criteria we are interested in."

Within 60 days, the city expects to solicit new proposals for the building - perhaps a badly needed public safety headquarters or something new from The Leonardo.

"Based on the past six years of experience, the city administration is skeptical The Leonardo can deliver a reliable program and succeed in the long run," Becker writes the City Council in a piercing appraisal that forced The Leonardo board to call an emergency weekend meeting.

"We are disappointed that, without thoroughly reviewing our new, reasonable proposal, and without meeting with or even notifying The Leonardo board or management team, Mayor Becker has submitted an opinion to the City Council that is inaccurate and highly prejudicial against The Leonardo," spokesman Patrick Thronson said. "Mayor Becker's actions show a lack of consideration for voters, who approved a $10 million bond specifically for The Leonardo in 2003, and for the generous donors who have contributed millions of dollars to build the project at Library Square. We urge him to reconsider and allow The Leonardo to have a fair hearing on Tuesday."

That's when the City Council will hear from both Becker and the museum's management team, which wants to use the bond plus $6 million in donations to open a stripped-down model in fall 2009. That plan calls for two additional phases, for $10 million total, in future years.

"Body Worlds," a popular exhibit scheduled by The Leonardo to open in the building Sept. 19, still is set for its four-month run.

Nancy Tessman, the capital's recently retired library director, argues The Leonardo's new pitch would work. "I was delighted to learn of this very viable alternative to the more expensive scheme."

But a new independent audit that shows considerable funding challenges for the museum and just $112,865 in the bank, gives Becker pause. Based on the original renovation plan, the museum still is $29.5 million shy, the audit shows, while $4.6 million of the $7.7 million in reported donations already has been spent.

"There is nothing firm in terms of how they would finance getting there," said Becker, who called it "fiscally irresponsible" for the city to commit public funds exclusively toward the museum.

The Leonardo failed to persuade Sorenson Legacy Foundation to pay for naming rights, which board members hoped would generate $5 million or more.

Still, The Leonardo team takes issue with the mayor's financial analysis, as well as a charge leveled in the audit that the museum breaks its monthly budgets. Thronson insists The Leonardo has been under budget for three consecutive years.

Talk of delays is unfounded, he adds, noting most museum projects take 10 years to complete.

What's more, Leonardo brass bristles over the green-building debate. While Becker demands a silver certification in Leadership in Energy and Environmental Design - he doubts Leonardo can get there - Thronson notes that city rule went into effect after the 2003 bond vote. Even so, Thronson says there is a "good chance" the museum could achieve LEED silver.

The Leonardo also would foster education and spur innovation for science and the arts, organizers argue.

"Is Mayor Becker contemplating a use for the building that would be of greater benefit to our city?" Thronson asks.

"Not necessarily," Becker said when asked if he had other uses in mind. Ideas have been floated, he added, but nothing formal.

Councilman Carlton Christensen says he is glad Becker has the "courage" to take a stand "that is not politically easy."

He says he shares the position, noting it would be "disingenuous" to residents to spend the bond on a scaled-back plan.

Instead, he said, "we have a fair chance of getting other proposals."

Jill Remington Love, council chairwoman, predicts the city will give The Leonardo time during the "Body Worlds" exhibit but that it will also examine other options.

djensen@sltrib.com

Mayor Becker's actions show a lack of consideration for voters, who approved a $10 million bond specifically for The Leonardo in 2003, and for the generous donors who have contributed millions of dollars to build the project at Library Square.

- Spokesman Patrick Thronson, said of Mayor Becker's opinion to the City Council

* The City Council on Tuesday will weigh The Leonardo's scaled-back proposal for the former main library as well as Mayor Ralph Becker's recommendation to consider new options.

* At issue is whether to release $10 million for the science and cultural center, a bond voters approved in 2003.

* The work session is scheduled for 3 p.m. at City Hall, Room 326.