New Jersey sued Amazon.com on ​Tuesday, accusing the online retailer of abusing its market power over ‌independent delivery drivers in the state.

Amazon used its dominance to impose low pay and poor conditions on thousands of New Jersey workers who deliver for the company via its ​Delivery Service Partner program, the state alleged in the lawsuit filed in federal ​court in Newark, New Jersey.

"This complaint is not grounded in ⁠fact," said Steve Kelly, an Amazon spokesperson.

Attorney General Jennifer Davenport's office said ​it was the first lawsuit in which a state has accused a company ​of illegal conduct to protect a monopsony, a market structure where one buyer controls the market.

"One corporation wins, the rest of us lose," Davenport said at a press conference.

The Delivery ​Service Partner program is run by Amazon's logistics arm and allows people ​to set up businesses to deliver packages locally. Those small businesses deliver 20 million ‌packages a ⁠day for Amazon globally, according to the company.

The state alleges that Amazon punishes drivers who try to unionise and tries to keep independent businesses in the program from poaching each other's drivers in violation of antitrust law.

Kelly, ​the Amazon spokesperson, said ​Davenport's office had ⁠not raised its main claims to the company before filing the lawsuit and that the allegations about the program and driver ​working conditions are "just wrong."

"DSPs manage their drivers' workday and route ​execution, ⁠and DSP employees are free to choose their employer and associate with who they want, full stop," he said.

Amazon is fighting other antitrust lawsuits brought by ⁠the U.S. ​Federal Trade Commission and the state of ​California, accusing the company of illegally monopolising online retail markets. The company has denied those allegations.