The Chamber of Commerce announced today that it spent $34.7 million on lobbying activities during the third quarter -- double the amount that the group spent in the first and second quarters combined.

The business group is vocally lobbying on two of the biggest issues on Capitol Hill: health care reform and climate change legislation. On health care, the Chamber opposes a public option or employer mandate, and on climate change the group opposes legislation passed by the House but supports an international agreement to reduce carbon emissions.

The Chamber already occupied the top spot in Under the Influence's list of "Top Health Care Players" for lobbying expenditures in the first half of the year, after spending about $10 million in the first quarter and about $7.4 million in the second quarter.

The Chamber spent $20.6 million on all lobbying activities during 2008's third quarter.

Lobbying disclosure forms for the third quarter are due Tuesday. Third-quarter information for other top-spending groups is not yet available.