The Federal Trade Commission looks set to drag Amazon into another legal battle between the two sides. The agency is preparing to file an antitrust suit against Amazon as soon as next week, according to Bloomberg. Reuters reports that the FTC has sent a draft complaint to attorneys general in an attempt to get as many states as possible on board with its case.

The details of the long-awaited legal challenge are not known as yet. It’s anticipated that the FTC will take aim at Amazon Prime, as well as claims that Amazon pushes third-party sellers to use its logistics and advertising services. The FTC is also said to believe that Amazon has rules to prevent products from being sold for less on rival platforms, which could be a factor in the suit (California has sued Amazon over that alleged practice).

The FTC has been scrutinizing Amazon for several years. If it files suit next week, that will mark the fourth action it has taken against the company this year. In May, the agency sued Amazon over children’s privacy concerns related to Alexa and claims that it was snooping on Ring users. Amazon paid a total of $30.8 million to quickly settle charges in both cases.

The following month, the FTC filed another complaint against Amazon, this time claiming that the company coerced people into signing up for a Prime subscription then making it difficult for them to cancel. That case is still ongoing. This week, the agency added three Amazon executives as defendants. It claims those individuals rebuffed pleas from Amazon employees to stop using deceptive tactics to trick people into signing up for a recurring payment through Prime.