Citing concerns that anonymous witnesses could be publicly identified, Rep. Jeff Flake (R-Ariz.) will revise a privileged resolution demanding the House ethics committee reveal to Congress the details — including witnesses, subpoenas and documents — of its investigation of earmarks Members provided to clients of the PMA Group lobbying firm.

Flake, who had introduced the resolution Tuesday, will not bring the matter to the floor Thursday, his office said, and will reintroduce a modified version of the resolution next week.

The Arizona lawmaker decided to change course after another Member raised concerns that Flake’s current resolution would require the committee to name every witness, even those who cooperated on the condition of anonymity.

“Congressman Flake recognizes that that is a valid concern,” Flake spokesman Matt Specht said.

Instead, Flake will request the committee identify the number of witnesses it interviewed, rather than their identities.

The ethics committee at the end of February issued a report exonerating several House Members of any improper activities relating to PMA, the lobbying firm that was raided by the FBI in late 2008 as part of an investigation into improper campaign contributions.

But Roll Call reported Monday that the ethics committee apparently interviewed no Members who were closely linked to PMA, and almost no staff, either. Roll Call did not locate any PMA client firms that had been contacted by the ethics committee.

The Office of Congressional Ethics had filed reports with the ethics committee on seven members of the House Appropriations Subcommittee on Defense, recommending that the committee open broader investigations of two Members, Reps. Todd Tiahrt (R-Kan.) and Peter Visclosky (D-Ind.). The OCE also suggested the ethics committee issue subpoenas to force cooperation by some companies. The committee decided instead to close the investigations of all seven Members.