US House Judiciary Committee Chairman Jim Jordan on Wednesday issued subpoenas to the chief executives of some of the tech industry’s biggest companies as Republicans on the committee press concerns over content moderation and free-speech issues.

The letters (PDF) demand that Google CEO Sundar Pichai, Amazon CEO Andy Jassy, Apple CEO Tim Cook, Meta CEO Mark Zuckerberg and Microsoft CEO Satya Nadella surrender documents related to communications between the companies and the Biden administration. Republican lawmakers have accused the companies of colluding to suppress conservative voices on their platforms, a claim the companies have denied.   

“To develop effective legislation, such as the possible enactment of new statutory limits on the executive branch’s ability to work with big tech to restrict the circulation of content and deplatform users, the Committee on the Judiciary must first understand how and to what extent the executive branch coerced and colluded with companies and other intermediaries to censor speech,” said Jordan’s letters to the CEOs.

Jordan, a Republican from Ohio, became chairman of the Judiciary committee last month after the GOP took control of the House, a position that includes the power to issue subpoenas. Jordan’s letters placed a March 23 deadline for the companies to turn over the documents.

Jordan suggested in the letters Wednesday that Twitter CEO Elon Musk was exempted from the subpoenas because the company “recently set a benchmark for how transparent Big Tech companies can be about interactions with government over censorship” through its release of the internal communications dubbed the Twitter Files, which discussed the platform’s decision to limit the reach of a New York Post article about President Biden’s son, Hunter Biden, ahead of the 2020 election.

A Microsoft spokesperson said it had “started producing documents, are engaged with the committee, and committed to working in good faith.”

Neither Alphabet, Apple nor Facebook immediately responded to a request for comment.