(Reuters) - A senior Democratic lawmaker on Tuesday urged the Obama administration to prod Republicans into action on a free trade pact with South Korea by "immediately" sending Congress a draft implementing bill.

"Congress should approve the U.S.-Korea free trade agreement before Memorial Day," Representative Sander Levin said at the Peterson Institute for International Economics.

Levin, the top Democrat on the House of Representatives Ways and Means Committee, criticized Republicans for refusing to move ahead on the Korea agreement until the White House sends Congress implementing bills for two other long-delayed trade agreements with Colombia and Panama.

He said the tactic "minimizes the importance of the Korea FTA," the biggest of the three agreements left over from the administration of former President George W. Bush, and "maximizes partisanship" on trade.

"USTR Ambassador Ron Kirk should send the draft implementing legislation to Congress immediately," Levin said, referring to the first step in the traditional process used by the White House for crafting a trade pact implementing bill.

Then, "after a reasonable period for consultation (based on the draft bill), the administration should formally send the (final) implementing legislation so that it can be introduced and 'fast track' procedures, including the specific timelines for consideration, started," Levin said.

Fast track refers to previously passed legislation that allows the White House to submit trade agreements to Congress for a straight up-or-down vote, without any amendments, within 90 legislative days.

Carol Guthrie, a spokeswoman for the U.S. Trade Representative's office, said it was Obama's goal to send all three trade agreements to Congress and noted the Korea pact was "ready for immediate consideration."

"We are working hard to resolve outstanding issues and advance the Colombia and Panama agreements as well. That timing will be determined by the outcome of our ongoing engagement with those governments," Guthrie said.

COLOMBIA ACCORD TOUGHEST

Republicans broadly support the Korea agreement, but have threatened to block a vote on the pact unless the White House also submits the Colombia and Panama deals for approval.

Levin said he believed the Korea pact would pass if the White House sent it to Congress, and urged the Obama administration to "be confident and proceed."

The Colombia agreement is by far the most controversial of the three pending agreements, and is strongly opposed by the AFL-CIO labor federation which complains the country has not done enough to protect workers rights and stop anti-union killings and other violence.

The Obama administration has been in talks with the Colombian government in the hope of striking a deal on the labor and violence issues that would allow the trade pact to move forward. Top Colombian officials were back in Washington on Tuesday to continue those discussions.

Levin, who has been one of Colombia's toughest critics in Congress, said the administration of new Colombian President Juan Manuel Santos has shown much more willingness to address the longstanding concerns than its predecessor.

"We must seize the opportunity presented by the Santos administration to assure concrete lasting changes to the conditions in Colombia," Levin said.

The 15-term congressman also called for immediate renewal of a trade preference program that since the early 1990s has allowed Colombia and other Andean countries to ship most of their goods to the United States without paying duties.

Efforts to renew the recently expired program, and another much larger trade preference program for over 130 developing countries, have become entangled in the stand-off over the three free trade agreements.

The Colombian government on Tuesday said it sent roses to every member of Congress to draw attention to more than 500,000 Colombian jobs it said have been put at risk because of the expiration of the program.

Flowers are one of Colombia's biggest exports to the United States under the Andean trade preference program.

Source: Reuters