The Small Business Administration has so far not made public the list of roughly 4.6 million businesses that have received more than $512 billion from the pandemic emergency lending program since early April. The agency is holding out despite growing demands for the data from government auditors, media companies, public interest groups and Republicans and Democrats in Congress. All contend disclosure is essential to determine whether the huge program is working as intended.

“We will have PPP loan disclosure,” Sen. Marco Rubio (R., Fla.), chairman of the Senate Small Business Committee, wrote Tuesday on Twitter.

Mr. Rubio, who has worked closely with the Trump administration on the PPP, said that there is “no dispute over larger loan recipients being disclosed” but that discussions were still under way on “how to treat smaller loans to mostly micro-business, sole proprietors & independent contractors.”