Parler claims it was also dropped by Slack after Amazon and other tech giants cut ties with the controversial social media company

• Parler CEO John Matze claimed in a court filing Wednesday that Slack had "canceled their services" to his company.
• Matze claimed, in a lawsuit against Amazon's AWS over its decision to cut ties with Parler, that Slack had cited "a violation of their own terms of service based on AWS's decision to drop Parler."
• "Losing Slack makes it extremely difficult to effectively enforce our terms of service with our almost 600 volunteer and paid Jury members," Matze said.
• Major tech companies including Amazon, Twilio, Apple, and Google have cut ties with Parler in recent days amid widespread reports that rioters used the app to organize and incite violence at the US Capitol last week.

Slack has joined the growing list of tech companies refusing to do business with Parler, according to Parler CEO John Matze.

"Slack Technologies, which provided a chat messaging system for coordinating with the Parler Jury that enforces our terms of service, abruptly canceled their services to Parler," Matze claimed in a court filing Wednesday.

Slack did not respond to a request for comment on this story.

Matze submitted the filing as part of Parler's antitrust lawsuit against Amazon's cloud computing arm, Amazon Web Services.

Parler filed the lawsuit on Monday after AWS cut ties with the controversial social media company amid widespread reports that rioters who seized the US Capitol last week had used Parler to organize and incite violence.

"AWS's highly publicized break... allowed the media to mischaracterize Parler in ways that have alienated Parler's partners," Matze claimed, adding that, in canceling its contract with Parler, Slack cited "a violation of their own terms of service based on AWS's decision to drop Parler."

"Losing Slack makes it extremely difficult to effectively enforce our terms of service with our almost 600 volunteer and paid Jury members," Matze said in the filing.

Parler has faced massive fallout in the wake of last week's violence as various business partners have cut ties.

Apple and Google removed Parler's app from their app stores, also citing its alleged refusal to take down violent content. Not long afterward, many of Parler's service providers, including Twilio, Okta, and Zendesk, removed Parler from their platforms as well.

Parler's platform was knocked offline over the weekend after AWS suspended its contract, and with Google Cloud, IBM, and Oracle all refusing to take on Parler, the company has reportedly enlisted the services of Epik, a domain registrar known for hosting far-right content.

Read more: Inside the rapid and mysterious rise of Parler, the 'free speech' Twitter alternative, which created a platform for conservatives by burning the Silicon Valley script

Parler rose to notoriety in recent months as mainstream social media sites have faced increasing pressure to crack down on hate speech, misinformation, and calls for violence.

Following the US presidential election in November, Trump supporters flocked to alternative social networks, including Parler, to plan election protests after Facebook and other sites banned groups that pushed debunked conspiracies. From November 3 to November 9, Parler was downloaded around 530,000 times in the US, according to data from Apptopia.