The latest development strains relations between the Christian Democrats and their "honorary chairman" to breaking point, and raises the prospect that this century's longest-reigning German leader might be forced out of his party and parliament.
The statement demanding Mr Kohl respond to accusations that his government was up for sale comes from the party's presidium, which met yesterday in Berlin to discuss the latest auditors' report. After the meeting, Wolfgang Schauble, the party's chairman, said that Mr Kohl's banking transactions in the 1990s could not be followed through existing files.
Mr Schauble was especially keen to discover who had given Mr Kohl, as he admitted, up to DM3m (pounds 1m) in cash. The former chancellor has said he cannot reveal the donors because he had promised them that he would not squeal.
After much oblique comment thrown in their honorary chairman's direction over the past days, the party's patience snapped yesterday, instructing him directly to name the donors. "This is absolutely necessary to prevent further damage to the party," Mr Schauble said. "There is no alternative."
Mr Schauble was for many years Mr Kohl's closest friend and loyal deputy, but has evidently now decided not to go down with his former boss. Another Christian Democrat leader going through this metamorphosis is Angela Merkel, the party's general secretary, groomed for years by Mr Kohl and once described by him as "my spiritual daughter".
Ms Merkel is now Mr Kohl's bitterest enemy. In yesterday's Frankfurter Allgemeine, she launched an attack on her former mentor. "Kohl's acknowledged actions have caused damage to the party," she wrote. "It's up to us to take our future into our own hands."
A parliamentary hearing into Mr Kohl's affairs has begun, but it is not likely to question the former chancellor until next year. Also pending is a criminal investigation against him by prosecutors in Bonn.