Faced with a historical district rezone that strips their property millions of dollars in value, the family that owns the Showbox theater is suing the City of Seattle for locking the land away from development by adding the venue into the Pike Place Market.

The lawsuit, filed Wednesday in King County Superior Court, demands that the city council either rescind the Aug. 13 council decision to rezone the parcel or, if the city declines, to pay $40 million in property value in exchange for the “taking” of the property. The council unanimously voted to protect the land following public backlash about a developer’s plan to tear down the popular music venue to make way for a 40-story apartment complex.

The rezone vote decision prompted the prospective developer, the Onni Group to withdraw from contract to purchase the land. And Onni’s withdrawal from the deal prompted the lawsuit.

Brad Keller, attorney for the Roger Forbes family which owns the property, said what the city did was illegal both from constitutional and property law standpoint. He said courts in Washington have not looked too kindly on so-called “spot zoning.”

“The city cannot discriminate against an individual property (by taking) that property — as it did here — and pluck it out of the middle of a block and say ‘only that property are we going to down zone it and say that you cannot build a high-rise there whereas everyone on that block can,’ ” he said in an interview. “Whatever the Seattle city council’s intent was, the reality is that the ordinance that it enacted is an illegal spot zone.”

The Seattle city attorney’s office couldn’t be reached for comment.

Read the full lawsuit here.