A last-minute legal challenge to Monday’s planned sale of bonds for the new Minnesota Vikings stadium could keep the field from opening in 2016.

At a hastily called news conference on Sunday, state officials said the sale of $468 million of stadium bonds had been unexpectedly halted.

Stadium leaders hope the Minnesota Supreme Court will rule quickly on issues raised in a Friday afternoon filing with the court, but said even a two-week delay in the bond sale could add a year to the stadium’s ambitious construction schedule.

“Major problems will result from any significant delay,” Michele Kelm-Helgen, chairwoman of the Minnesota Sports Facilities Authority, said Sunday in a conference call that also included state Management and Budget Commissioner Jim Schowalter. The authority will own and operate the $1 billion stadium slated to open in July 2016 on the Metrodome site.

“We will be short $28 million if we are not able to pay our bills [without bond proceeds] … by the end of the month. Architects and Minnesota companies have done work in the past month and submitted bills due at the end of January,” said Kelm-Helgen. She said bond funds need to be available by Jan. 23 to avoid delays that could postpone the stadium opening for a year. The delay could also jeopardize the Downtown East park and business development, she said.

The “petition for a writ of prohibition” was filed by three Minneapolis residents: former mayoral candidate Douglas Mann, his wife, and former city school board member David Tilsen.

Mann said the bond sale is unconstitutional and should be stopped because it depends partly for repayment on Minneapolis dedicating sales tax revenues to that purpose. He said the city should hold a referendum and let voters decide if they want to fund a new stadium. Mann said he filed a similar lawsuit last summer against the city and has appealed an adverse district court ruling in that action.

The state is required to disclose any pending legal actions when bonds are sold, according to federal law and Securities and Exchange Commission regulations, Schowalter said.