The White House said it will not allow most of its policy "czars" to testify before Congress.
The Washington Times reported last week that concerned senators want more access to the czars.
Sen. Susan Collins, R-Maine, said some of the 18 czars do more than just advise the White House. They create policy.
"I think Congress should be able to call the president's climate czar, Carol Browner, the energy and environment czar, to ask her about the negotiations she conducted with the automobile industry that led to very significant policy changes with regard to emissions standards," Collins said at a hearing Thursday that examined the proliferation of czars.
Collins also said few czars, if any, have been confirmed by the Senate.
The White House sent a letter to Collins, saying that the president is not trying to circumvent Congress.
Critics charge that the czars' power to write policy in secret violates Obama's promise to have an open and transparent presidency.
*Originally published October 26, 2009.