Tobacco stocks plunged after a report said the U.S. government may only allow cigarettes with nicotine levels so low they’d no longer be addictive, and may also move to ban menthol.

The U.S. Food and Drug Administration is expected to rule on menthol cigarettes by the end of the month under pressure from a deadline in a lawsuit. The agency said years ago it would consider lowering nicotine levels in cigarettes. The Wall Street Journal reported Monday that the Biden administration agency is considering the ban, along with requirements to lower nicotine content, citing people familiar with the matter.

Marlboro producer Altria Group Inc. fell as much as 6.9% Tuesday, losing more than $11 billion in market value since Friday. British American Tobacco Plc dropped as much as 8.3% in London Tuesday. Analysts estimate the maker of Lucky Strike cigarettes gets as much as a third of its earnings from menthol brands such as Newport.

The FDA declined to comment on the report on Monday. The Wall Street Journal said the Biden administration is weighing whether to enact a menthol ban or nicotine restrictions, or both.

Imperial Brands Plc, which makes Kool cigarettes, fell as much as 7.5%. Stock of 22nd Century Group Inc., which already sells cigarettes with very low nicotine levels, extended Monday’s 11% gain.

The industry has been anticipating an FDA decision about nicotine levels in cigarettes for years. The agency declared in 2018 that it intended to do so, prompting Altria to question whether that’s technically achievable and if that would effectively reduce smoking. Since then, 22nd Century Group, based in Williamsville, New York, has come out with reduced-nicotine cigarettes.

Philip Morris International Inc. was little changed Tuesday after raising its outlook for the year amid stronger demand for its IQOS cigarette alternative. Philip Morris, which doesn’t sell cigarettes in the U.S., dropped only 1.3% Monday, outperforming rivals on the prospect that tighter tobacco rules could spur demand for IQOS. Altria sells the product in the U.S. through an alliance.

In an email, Altria said any FDA action “must be based on science and evidence and must consider the real-world consequences of such actions, including the growth of an illicit market and the impact on hundreds of thousands of jobs.”

The proposal on nicotine is serious, but politically would be difficult to pull off, according to Adam Spielman, an analyst at Citigroup. Some 15% of voters smoke, and such a move could cost Democrats large numbers of blue-collar votes.

“We suspect that this idea will continue to be discussed for decades, but we would be extremely surprised if it were implemented in the next 10 or even 15 years,” he wrote in a note.

BAT’s Reynolds unit said there are better ways to improve public health and reduce the harm from tobacco.

“Many consumers wrongly believe that a cigarette very low in nicotine content is lower in risk than traditional cigarettes, a misconception that poses a major hurdle in determining proposed rulemaking for low nicotine cigarettes,” the company said.

One issue is that such a rule might lead some smokers to consume more cigarettes as they seek a fix to their nicotine cravings, inhaling more dangerous chemicals in the process. It could also create a black market for more powerful cigarettes.

The FDA has been expected to state its position on whether it would still allow menthol cigarettes by April 29, under a deadline imposed by a lawsuit. The case, brought by the African American Tobacco Control Leadership Council, had sued the government agency saying it had taken an unreasonably long time to respond to a citizen’s petition filed years ago that sought to prohibit menthol as a flavor in cigarettes.

With assistance from Marthe Fourcade.