A ruling in a US state court has raised questions about whether Detroit's bankruptcy will stand up under legal review.
The state court judge in Michigan's capital of Lansing ordered Detroit's Emergency Manager Kevyn Orr to withdraw the bankruptcy petition because the state law that allowed Michigan Governor Rick Snyder to approve the bankruptcy violated the Michigan Constitution.
Orr, who was appointed by Snyder in March to try to resolve the city's financial crisis and tackle its $18.5 billion in long-term debt, acknowledged that court battles over the need for a bankruptcy filing could be protracted and difficult.
Once a powerhouse of the US car industry, Detroit has filed for bankruptcy as it owes creditors almost $20bn it cannot pay.
Detroit, once a booming American metropolis, has become the largest US city to file for bankruptcy, with debts of at least $18bn.