Democrats in Congress have demanded that some of America's biggest companies hand over records of their donations to President Donald Trump's White House ballroom, warning that they could face subpoenas once the new Congress takes power in January.

Senator Richard Blumenthal, who is set to chair the Senate Permanent Subcommittee on Investigations when Democrats take control, sent the demands on Thursday, 5 November. Apple, Meta, Google, Nvidia, Amazon and Microsoft were among the companies told to turn over records voluntarily, Reuters reported.

Blumenthal warned the companies that if they do not hand over the documents when Democrats take control in January, "it will leave the subcommittee with no choice but to consider alternative measures to obtain compliance" — in other words, subpoenas. The companies did not immediately respond to requests for comment.

The ballroom project was funded with about $333 million in private donations, according to the Washington Post. Apple and Nvidia each committed $25 million, among the largest individual pledges. The Adelson family and Charles Ergen, co-founder and chairman of Dish Network, also committed $25 million each, the Post reported. Federal contractors including Lockheed Martin, Microsoft and Palantir each gave $10 million.

Other recipients of Blumenthal's letters include Comcast, BlackRock, Booz Allen, Caterpillar, Cisco Systems, Salesforce, HP and Micron. Blumenthal has previously noted that many of the donors "have deep financial, business, or other personal interests before the Administration", raising questions about whether donations bought access or favour.

The demands are an early sign of how Democrats plan to use their new majorities after winning control of both chambers of Congress in Tuesday's midterm elections. The party has spent the past two years largely unable to compel documents from major companies and the Trump administration, and its leaders have signalled that oversight will be a priority from January.

Blumenthal also demanded documents from Brendan Carr, chair of the Federal Communications Commission, about the agency's handling of investigations into media companies and its approval of the Paramount Skydance merger last year. He criticised Carr's decision to order an early licence review of Disney's eight company-owned ABC stations, saying Carr's actions "erode and undermine freedom of speech and freedom of the press and bear on the laws governing media consolidation".

The ballroom inquiry is part of a broader Democratic investigative push. According to the Washington Post, lawmakers are also preparing scrutiny of Apple over tracking applications used by US Immigration and Customs Enforcement, of Meta over non-disclosure agreements tied to data-centre development, and of companies linked to Elon Musk, including the reported use of his Grok chatbot in planning the operation that led to the capture of Venezuela's President Nicolas Maduro.

Incoming House Oversight chair Robert Garcia and other Democrats have signalled aggressive oversight of corporate dealings with the administration, including donations, gifts and access that some Democrats describe as potential quid pro quo arrangements. No finding of wrongdoing has been made against any donor, and the demands so far seek records rather than making accusations. But with subpoena power arriving in January, the companies face a choice between voluntary cooperation now or compelled disclosure later.