An association of food and drink makers will continue to fight a record $18 million fine levied against it for concealing the names of companies that spent heavily in 2013 to defeat a GMO-labeling initiative in Washington.

A Consumer Brands Association spokeswoman said Wednesday the group plans to appeal its latest setback to the state Supreme Court. If that fails, the association may go to the U.S. Supreme Court, she said.

“The ruling is clearly disproportional to other campaign finance violations of its kind, and we will continue to exhaust a series of legal options,” the spokeswoman said in an email.

The Washington Court of Appeals Division II on Tuesday rejected that association’s claim that the penalty violated the Eighth Amendment’s prohibition against excessive fines.

The unanimous three-judge panel said the penalty was warranted because voters were unable to follow who was spending to defeat an initiative that would have required GMO ingredients to be listed on the labels of some foods.