In advance of a hearing Tuesday, the Senate Finance Committee’s leaders have fired off a letter to the IRS seeking answers to 41 questions and requesting documents about the criteria used for targeting tea party and other groups.

Chairman Max Baucus, D-Mont., and his GOP ranking member, Orrin G. Hatch of Utah, want details from outgoing IRS acting Commissioner Steven Miller of every IRS employee who had any knowledge of the procedures used by IRS officials in Cincinnati in reviewing applications for nonprofit tax status.

“Targeting applicants for tax-exempt status using political labels threatens to undermine the public’s trust in the IRS. Lack of candor in advising the Senate of this practice is equally troubling,” the senators said in their letter.

The two senators also requested a slew of answers and documents by the end of the month — ideally in formats that investigators will be able to sort.

“[T]he information requested and documents should be provided, where possible or practicable, in a searchable or sortable electronic format, such as Excel or PDF,” wrote Baucus and Hatch.

Baucus and Hatch will convene a Finance hearing Tuesday morning that will feature testimony from Miller, former IRS Commissioner Douglas Shulman and Treasury Inspector General for Tax Administration J. Russell George.

The Finance hearing follows one last week at the House Ways and Means Committee; our colleagues at the Goppers blog have more on that hearing.