There's still some doubt about whether ranked-choice voting will go ahead this fall in Minneapolis, despite strong backing from voters and a judicial slapdown to a legal challenge.

The City Council told its election staff on Thursday to keep working to implement the new voter-approved system in which voters rank candidates in order of preference. But it also directed the staff to prepare a contingency plan for a traditional election.

The main reason for uncertainty is an appeal by the Minnesota Voters Alliance of a Hennepin County District Court ruling against its challenge to the constitutionality of the law. Although both sides are asking the Minnesota Supreme Court for an expedited appeal, the city seeks an answer by June so it can decide which method to use.

If the alliance seeks federal review of that state appeal, as it says it would do if it doesn't prevail, that could push the legal outcome well past June.

City Attorney Susan Segal warned of "significant risks" of conducting a ranked-choice-voting election before appeals are exhausted. One is that an overturning of a ranked-choice election by courts could require a new election. Theoretically, that could leave no one running the city if the new election weren't held until after current terms run out on Jan. 4, she said.

Segal and representatives of Minnesota FairVote, which campaigned for the new method, expressed confidence that ranked-choice voting is on strong legal footing. Jeanne Massey, FairVote's executive director, said it was pleased with the council's direction. Andy Cilek, the alliance's executive director, also said the dual-track approach makes sense.

Voters approved ranked-choice voting in a 2006 referendum by a margin of almost 2-1. It will be used in mayoral, council, Park Board and Board of Estimate contests. It must be implemented in 2009 or the council will need to adopt an ordinance by four months before the election stating why it is sticking with the traditional method for 2009.