Elon Musk’s X has filed a bombshell antitrust lawsuit against a left-leaning advertising cartel and several member companies on Tuesday for allegedly targeting the site with an illegal ad boycott.

In an open letter addressed to advertisers, X CEO Linda Yaccarino said the lawsuit will target the Global Alliance for Responsible Media, its parent firm World Federation of Advertisers (WFA) and GARM members CVS Health, Mars, Orsted and Unilever.

The lawsuit came on the heels of a damning report by the House Judiciary Committee, which accused GARM and its members of coordinating an effort to suppress online free speech and restricts ads to a slew of news outlets — including The Post.

X owner Elon Musk is pictured. AFP via Getty Images

Filed in Texas federal court, the lawsuit seeks trebled compensatory damages and injunctive relief, according to a copy of the complaint viewed by The Post.

“To put it simply, people are hurt when the marketplace of ideas is undermined and some viewpoints are not funded over others as part of an illegal boycott,” Yaccarino said. “This behavior is a stain on a great industry, and cannot be allowed to continue.”

“This is not a decision we took lightly, but it is a direct consequence of their actions,” Yaccarino added. “The illegal behavior of these organizations and their executives cost X billions of dollars.”

The Global Alliance for Responsible Media, or GARM, is an initiative of the World Federation of Advertisers. The WFA represents dozens of the world’s largest companies and ad organizations, including the likes of Disney and Coca-Cola.

Its members control 90% of global marketing spending, amounting to nearly $1 trillion per year, according to the House Judiciary Committee’s report.

“This case is about more than damages – we have to fix a broken ecosystem that allows this illegal activity to occur,” Yaccarino added.

X CEO Linda Yaccarino announced the legal action in an open letter. Getty Images

Much of the House committee’s scrutiny fell on GARM’s far-left boss Robert Rakowitz. Lawmakers obtained internal emails, including one in which Rakowitz appeared to brag that X was “80% below revenue forecasts” since GARM targeted Musk over brand safety issues.

Rakowitz later claimed the email was meant as a “self-effacing joke.”

The House committee’s probe focused on whether GARM and its members violated Section 1 of the Sherman Antitrust Act, which governs illegal restraint of trade.

Sources previously told The Post that the panel was considering whether to make an official referral to the Justice Department.

GARM is an initiative of the World Federation of Advertisers.

GARM is alleged to have steered ad dollars away from a number of other right-leaning outlets, including Fox News and comedian Joe Rogan’s podcast “The Joe Rogan Experience.”

GARM has pushed back on the claims, with a spokesperson previously asserting that the committee’s allegations of anti-competitive behavior are “unfounded.”

As The Post reported last week, the House Judiciary Committee sent letters to more than 40 major companies demanding more information about whether they colluded to defund news outlets and platforms that allowed political views with which they disagreed.

GARM chief Rob Rakowitz was scrutinized in the House committee’s report. AWNewYork/Shutterstock

Adidas, American Express, Bayer, BP, Carhartt, Chanel, CVS and General Motors were among the companies that received letters requesting that they preserve documents and provide information related to their dealings with GARM.

“The Committee has learned that collusive activity is occurring within the Global Alliance for Responsible Media, of which your company is a member,” the letter began.

“In particular, the Committee has uncovered evidence of coordinated action by GARM and its member companies, including boycotts of disfavored social media platforms, podcasts, and news outlets,” the letter added.

A House report alleged that GARM coordinated efforts to stifle ad dollars. SOPA Images/LightRocket via Getty Images

At least two Republican state attorneys general are known to be examining evidence surfaced by the House report and weighing possible legal action against the cabal’s members.

This is a breaking story. Check back for updates.