UPDATE: The FDA Food Safety Modernization Act, S.510, cleared the full Senate Tuesday by a vote of 73-25. See Food Safety News tomorrow for all the details. For live updates see the @foodsafetynews Twitter page.

The Senate food safety bill, which has been inching towards passage the past few weeks, cleared a key procedural hurdle Monday, but Senate leaders put off two votes on amendments and the final vote on the bill to Tuesday morning.

The upper chamber voted 69 to 26 to limit debate on the FDA Food Safety Modernization Act (S.510), which now includes a measure to exempt small farms and producers sponsored by Sen. Jon Tester (D-MT). The amendment, cosponsored by Sen. Kay Hagan (D-NC), has complicated the debate over the sweeping food safety legislation. The compromise to include a scaled-back version of the Tester-Hagan amendment got key sustainable agriculture groups on board, kept consumer groups in the fold, but isolated the biggest players in the fresh produce industry who have been working on the legislation for several months. (See: Politics, Small Farm Deal Stall Food Safety Bill, Nov 19, 2010)

The inclusion of Tester-Hagan also cost the bill one of its original cosponsors: Sen. Saxby Chambliss (R-GA). Chambliss took the floor of the Senate yesterday and said he regretted that he could no longer support S.510, because it had become so different from the legislation he originally backed.

After a few hours of debate that was largely focused on amendments to fix a burdensome paperwork glitch in the health care bill, the Senate began a heated discussion on an amendment by Sen. Tom Coburn (R-OK) to end legislative earmarks through 2013.

According to sources on the Capitol Hill, the Senate is planning to consider the controversial earmark moratorium and severely scaled back substitute amendment by Sen. Coburn. Coburn has become S.510’s fiercest opponent, citing the bill’s five-year, $1.4 billion price tag–which the Congressional Budget Office has deemed deficit neutral. Coburn also argues that the bill fails to address systemic problems with federal food safety oversight and will increase the cost of food as well as leave the states with unfunded mandates.

“It doesn’t [fix food safety].  What it does is it raises costs.  We’re going to increase the cost of food,” said Coburn, adding that his proposal would force the agencies to better coordinate.

Coburn argued that his amendment would fix the real food safety problem: ineffective government.

Sen. Tom Harkin (D-IA), chairman of the that unanimously approved the bill in November 2009, took the floor with a very different perspective.  Harkin argued that Coburn’s measure “kills the bill entirely.”

The U.S. Chamber of Commerce also weighed in Monday, issuing a statement of support for final passage for the manager’s amendment for S.510.  “This legislation would improve food safety by requiring all food manufacturers to develop a food safety plan, providing the U.S. Food and Drug Administration (FDA) with new tools to ensure the safety of imported food, and employing a rational, risk-based approach to inspection,” said Bruce Josten, the group’s executive vice president for government affairs.

Though it appears Democrats still have the coalition needed to get the legislation through the Senate, it remains to be seen whether the House will agree to take up and pass the Senate version of the bill.

Votes on the food safety bill and amendments are set to begin at 9:15 a.m. EST. If you’re on twitter, follow the debate at @foodsafetynews.