California's attorney general is suing ExxonMobil, alleging the oil giant engaged in a “decades-long campaign of deception” about the effectiveness of plastics recycling.

In the civil lawsuit filed on Monday, Attorney General Rob Bonta accused Exxon of contributing to a "deluge" of plastic pollution, while telling Californians that recycling was a fix.

"For decades, ExxonMobil has been deceiving the public to convince us that plastic recycling could solve the plastic waste and pollution crisis when they clearly knew this wasn’t possible,” Bonta said.

In a statement, Exxon blamed California for an inefficient recycling programme.

"For decades, California officials have known their recycling system isn't effective. They failed to act, and now they seek to blame others. Instead of suing us, they could have worked with us to fix the problem and keep plastic out of landfills," the company said in a statement.

An Exxon spokesperson added that the company had processed more than 60 million pounds (27 million kilograms) of plastic waste into usable raw materials, "keeping it out of landfills".

Bonta's office said the case marks the first time US officials have attempted to hold a gas or oil company accountable for deceptive claims about plastics recycling.

California is seeking an unspecified amount of money that Bonta said could come to as much as “multiple billions of dollars".

“ExxonMobil lied to further its [record]-breaking profits at the expense of our planet and possibly jeopardising our health," he said.

Last year, Bonta sued ExxonMobil as well as four other oil giants for compensation over climate change damages.

The most recent lawsuit, filed in San Francisco County Superior Court, comes after a nearly two-year investigation by Bonta's office into the fossil fuel and petrochemical industries and global plastics pollution.

ExxonMobil is the world's largest producer of resins used for single-use plastics, according a report by Australia's Minderoo Foundation.

Bonta alleged that, through its marketing, the company was promoting its "advanced recycling" programme to the public as a solution to plastic waste, while knowing that the company would "never be able to process more than a tiny fraction of the plastic waste it produces".

The 147-page suit alleges that nearly all of plastic waste processed by the company has been turned into fuel instead of recycled plastic.

The deception violated state nuisance, natural resources, water pollution, false advertisement and unfair competition laws, Bonta said.

The world produces over 400 million tons of plastic each year, but only 9% is recycled, according to a 2022 report from the Organisation for Economic Co-operation and Development.