The Biden transition team did not respond to several requests to comment.
The fight over these rules started quietly over the summer when Mr. Biden’s campaign invited dozens of ethics experts, professors and others, including advisers to Ms. Warren and other members of Congress, to make recommendations about an ethics policy to be issued on Day 1 of a possible administration.
While some argued that the Obama-era lobbying restrictions could hurt a Biden administration’s ability to recruit people with useful expertise, others pushed for tougher restrictions that bar not only lobbyists from being hired, but also corporate executives and consultants who advise companies on getting their way in Washington but do not register as lobbyists.
Progressives started growing concerned about Mr. Biden’s personnel moves even before the election, when he announced his first list of top transition advisers. It included Jessica Hertz, who helped oversee government relations efforts at Facebook, and Avril Haines, who worked at WestExec Advisors and also consulted for the data-mining company Palantir.
Mr. Biden’s first big move — naming Ron Klain on Wednesday as his chief of staff — drew praise from Ms. Warren and some progressive activists. They had worried that Mr. Biden might pick Steve Ricchetti, a close adviser and former pharmaceutical industry lobbyist who served as his chief of staff while he was vice president.
Mr. Klain has corporate ties, too. He has most recently worked with Steve Case, the founder of AOL, in a venture capital firm called Revolution, and he warned in 2015 about the impact that government regulation can have on technology start-ups.
Debates over personnel are common in new administrations, as interest groups and factions of supporters of an incoming president jockey for influence.
But they are likely to be particularly intense in the Biden administration after an election in which the liberal wing of the party suppressed its concerns about what they saw as Mr. Biden’s cautious centrism out of a desire to defeat President Trump. The stakes are heightened further by Mr. Biden’s pledge to differentiate his administration from Mr. Trump’s, in which representatives from corporate America and Wall Street held prominent posts, and conflicts of interest abounded.