A doctor who was banned from Twitter for posting about COVID-19 vaccines is willing to serve as the lead plaintiff in a potential class-action lawsuit against the social media company, his lawyer has informed the tech giant.

Dr. Andrew Bostom “stands with a growing number of similarly situated people who have had their Twitter accounts suspended for sharing their views and opinions on COVID-19,” James Lawrence III, Bostom’s lawyer, told Twitter in a letter dated Aug. 6.

“Dr. Bostom is ready, willing, and able to serve as a lead plaintiff in a class-action lawsuit against Twitter for breach of contract if that becomes necessary,” Lawrence added.

Bostom, with the Brown University Center For Primary Care and Prevention, was permanently suspended in June after sharing the results of a study that linked Pfizer’s COVID-19 vaccine with lower sperm and semen concentration in men.

After Lawrence contacted Twitter on Bostom’s behalf, the company reversed the suspension, admitting he did not appear to violate any rules with the post.