WASHINGTON - June 3 - Two of Washington, D.C.'s most reliable and respected nonpartisan watchdogs have once again joined forces, updating their one-of-a-kind, comprehensive database that links campaign contributions with earmarks of members of Congress.

"This unique database helps people investigate whether their elected officials might be doing special favors for special interests," said Sheila Krumholz, the executive director of the Center for Responsive Politics. "Taxpayer money requested for a lawmaker's friends or supporters represents a potential conflict of interest and warrants further scrutiny."

"This tool shines a light on the current system where millions of dollars in campaign contributions can turn into billions of earmarked tax dollars," said Ryan Alexander, president of Taxpayers for Common Sense. "Funding decisions must be based on project merit. With the nation facing enormous budget deficits, we cannot afford to waste a dime."

Members of Congress use "earmarks" to provide federal funding to companies, projects, groups and organizations, often in their district. The practice has come under intense criticism this year, with congressional Democrats banning earmark requests benefiting for-profit entities for fiscal year 2011 and congressional Republicans pushing their caucus to abstain from requesting earmarks across-the-board.

Last fiscal year, however, members of Congress obtained nearly 9,500 spending provisions -- worth over $15.9 billion -- for organizations that spent $269 million on lobbying, the Center for Responsive Politics and Taxpayers for Common Sense found.

These members of Congress also accepted more than $2.3 million from the political action committees and employees of the intended earmark beneficiaries -- of the $22.4 million these organizations donated to all federal candidates and parties, the Center for Responsive Politics and Taxpayers for Common Sense found.

User-friendly databases available at OpenSecrets.org and Taxpayer.net now provide detailed information on the number and value of earmarks members of Congress have requested during fiscal years 2008 through 2010.

The joint effort also showcases the data in a manner that is sortable in a variety of ways, including by House and Senate members, by recipients that lobby, by recipients with political action committees, by state and by legislation.

Some members of Congress don't request earmarks.

In fiscal year 2010, the collection of lawmakers not making earmark requests included several notable names from both the Republican and Democratic parties. Among them? Sen. John McCain (R-Ariz.), Sen. Claire McCaskill (D-Mo.), Sen. Russ Feingold (D-Wis.), Rep. Jeff Flake (R-Ariz.), Rep. John Boehner (R-Ohio) and Rep. Walter Minnick (D-Idaho).

On balance, Republicans were more likely to forgo earmark requests than Democrats last fiscal year.

The addition of fiscal year 2010 information augments data from fiscal years 2008 and 2009, which the watchdog groups released last year.