City suburbs attempting to halt rumoured sale of prestigious art collection, which may be up for grabs in bid to pay city's debts

The beleaguered city of Detroit, the largest in the US to file for bankruptcy, is embroiled in a fresh controversy over fears that it may be preparing to sell some of its 60,000-piece art collection, one of the most prestigious in the US.

Officials from suburban counties have warned that if the city's bankruptcy managers sell any assets in the Detroit Institute of Art (DIA) – whose collection includes a self-portrait by Van Gogh, a 27-panel fresco by Diego Rivera and works by Rembrandt and Matisse – they will cut their contributions to its funding. The combined income from three counties surrounding the city is worth $23m a year to the museum, a sum that represents almost 75% of its operating budget.

In a clear message to the city to ringfence the collection, officials from Oakland County will vote next Tuesday on a resolution to stop distributing a property tax levy if any art is sold or if funds from the museum are diverted to pay the city's creditors. Nearby Macomb and Wayne Counties have similar plans. The museum itself maintains that the artwork is protected by a charitable trust, a position with which emergency manager Kevyn Orr told Reuters last week he disagrees.

The prospect of putting the museum's art up for sale, alongside other assets such as the water and sewage department, has sparked fierce debate in city and beyond, as bankrupt Detroit looks for ways to raise cash to pay off its debt. On Wednesday, supporters of the museum, including art blogs and local websites, staged a day of action with posts about DIA treasures to draw attention to its plight.

Oakland County's move was sparked by renewed fears over the potential sale of art, after it emerged last week that bankruptcy managers had invited Christie's, the auction house, to value some of the collection. Michigan governor Rick Snyder and Orr have repeatedly said they don't want to sell the museum's assets, but Orr has also said he hasn't ruled anything out yet.

Nearby Macomb County said on Wednesday it intended to follow Oakland's lead. Officials from Wayne County reportedly have a similar plan.

If the levy from all three counties were stopped, the museum would "probably close" according to the DIA.

Brooks Patterson, the executive of Oakland County, told the Guardian the vote is meant to "raise a red flag" to the city.

"It is a warning. If they want to sell if off, then I can't stop them. But there are consequences, serious consequences" for any breach of contract. Detroit would be violating the counties' agreement with the DIA if it moved to sell any DIA exhibits to pay the city's debt after it filed for bankruptcy, he said.

Mark Hackel, the executive of Macomb County, told the Guardian it intended to pass a resolution similar to Oakland's.

"We've already talked about it, and the Macomb authority has the same mindset" Hackel said. "I talked to [Brooks Patterson] about it. People are adamant it shouldn't be sold. There's a concern that might happen. Simply put, we don't believe this has anything to do with the city of Detroit."

Taken over 10 years, income from the property tax levy from all three counties represents $250m to the institute, according to the OCAI.

The OCAI resolution states that "any use of funds received form disposition of works of art in the city art collection to satisfy city creditors" would constitute an "abrogation, cancellation" or other breach of the operating contract. So too, would use of any OCAI funds to support "new DIA lease or licensing agreement imposed by the city as a means to raise funds to satisfy city creditors" it said.

The possibility that city-owned art in the DIA collection might be sold as part of Detroit's plan to settle an estimated $18bn it owes to bondholders, pensioners and others, continues to be one of the most controversial aspects of the city's bankruptcy plan.

The contract between the counties and the institute stipulates that it should be operated in accordance with professional museum standards. These include a clause saying that the proceeds of art sold must be used to buy more art.

Selling artwork for other reasons breaches such standards, say representatives of the art institute itself.

The museum and Michigan attorney general Bill Schuette have said that the art cannot be sold because it is held in a charitable trust for the people of Michigan. Orr last week told Reuters he disagreed with that position.

However, Pamela Marcil, a spokeswoman for the DIA, said on Wednesday they were taking the continued threat to the collection seriously. She said that the news about Christie's engagement with the museum last week had sparked a new wave of protest.

"We are concerned any time it is even mentioned," Marcil said."The situation is unprecedented and no one knows what is going to happen."

But she warned that if the city did sell even a single work of art, "we would take it to court and it could be tied up for years."

No one from Synder's office or the office of the emergency was available for comment when contacted by the Guardian.

Orr's spokesman Bill Nowling told Reuters on Tuesday that the city does not plan to sell the DIA art but is open to alternative plans that may raise money for the city. He said that Christie's may provide options to a sale.

Nowling said: "Christie's wants to come to the table with alternatives that generate revenue, substantial revenue, without changing the ownership of the art," Nowling said. "They didn't just want to come and value the art. They wanted to come and find a solution that would preserve the art.