First it was the U.S. Chamber of Commerce's position on climate change legislation, now it's the group's stand on Democrats' health care reform measures that is causing headaches for the lobbying organization.

A group of faith-based institutional investors announced Tuesday they are pressuring 36 corporate members of the U.S. Chamber to publicly state whether the trade group's opposition to the health care bills wending their way through Congress is reflective of their company position on the issue. They are also asking the companies to push the chamber to play a more "helpful" role in the debate.

"Faith based investors already concerned about the 'disconnect' between the U.S. Chamber of Commerce and its leading members on climate legislation are now troubled to see the same dynamic at work on the health care reform bill," said Laura Berry, executive director of the Interfaith Center on Corporate Responsibility."

Berry's group said it has contacted 36 companies by letter or by phone asking them to clarify their position. All of the companies had previously "agreed at the urging of shareholders to embrace health care principles that are now inconsistent with the anti-reform stance" of the chamber.

The companies contacted include AT&T, General Electric, IBM, McDonald's, Merck, Starbucks, Verizon and Wal-Mart .

To see a copy of the letter, click here. The full list of the companies can be found here.

Among the investors sponsoring the letters are the AFL-CIO Office of Investment, Progressive Asset Management and Trillium Asset Management.