Stephen Tillery said his original argument the tobacco giant fooled customers into believing Marlboro Lights were lower in tar and nicotine than regular cigarettes was supported by the U.S. solicitor general in a separate case.
Tillery's claim had been overturned by the Illinois Supreme Court, which said the Federal Trade Commission had approved cigarettes' "light" label, so Philip Morris could not be held liable for any implications.
But in a new case -- Watson v. Philip Morris now pending before the high court -- Paul Clement, the federal government's primary Supreme Court advocate, said the trade commission never approved or ordered tobacco companies to label their products, The St. Louis Post-Dispatch reported.
"This is the federal agency saying the reason the Illinois Supreme Court dismissed our case was wrong," Tillery told the newspaper.
He argued Madison County, Ill., Circuit Judge Nicholas Byron, who dismissed the claim, should reopen the case.
Philip Morris lawyers countered there was no legal reason for Byron to have jurisdiction over a closed case.