UPDATE 2-US Senate to hold votes on healthcare amendments

* Senate leaders agree on first series of votes

* Democrats accuse Republicans of obstructing health bill

* Republicans say they are "just getting started" (Adds budget director, paragraph 14)

By John Whitesides and Donna Smith

WASHINGTON, Dec 2 (Reuters) - U.S. Senate leaders broke a logjam on a sweeping healthcare overhaul on Wednesday, reaching agreement to vote on four amendments after frustrated Democrats accused Republican opponents of stalling the bill.

Senator Dick Durbin, the Senate's No. 2 Democrat, said the Senate would vote on Thursday on two competing measures to ensure women have access to mammograms and other preventive screenings and two amendments on proposed spending cuts in the Medicare government health program for the elderly.

The agreement requires that the amendments, which include one offered by Republican Senator John McCain to strike Medicare spending cuts from the bill, win 60 votes in the 100-member Senate in order to pass.

Leaders agreed on the timing of votes on the first batch of amendments after Democrats accused Republicans of trying to stall the bill that President Barack Obama has made his top domestic priority.

Republicans argued the 2,074-page legislation that would revamp the $2.5 trillion healthcare system -- one-sixth of the U.S. economy -- deserved lengthy debate and had refused to reach quick agreement on the timing of the first votes.

Democrats said they would keep the Senate in session through the Christmas holiday if needed and considered filing motions to cut off debate or kill Republican amendments.

"Unless the Republican leadership comes forward with a reasonable approach to these amendments, I think our patience is wearing thin," Durbin said.

"We're not going to let them run this bill into the ground into next year," he told reporters. "They want to drag this out in the hopes that our desire to go home for Christmas means we'll walk away from healthcare reform."

The House of Representatives passed a healthcare overhaul bill last month. If the Senate passes a bill, the two versions will have to be reconciled and passed again by each chamber before being sent to Obama for his signature.

'JUST GETTING STARTED'

The slow pace and lengthy deliberations were a tradition of the Senate, Republicans argued.

"The people expect to have a right to weigh in," Republican Senator Lamar Alexander told reporters. "The Senate is a place where we have generally unlimited debate, generally unlimited amendments, so we're just getting started on this bill."

Republicans solidly oppose the Democratic-written bill and are planning dozens of amendments, many designed to highlight politically difficult Medicare spending cuts and other measures aimed at reining in soaring healthcare costs.

The AARP, the influential advocacy group for the elderly, backed Senate Democrats on Medicare spending, saying in a statement the proposed cuts would not harm guaranteed benefits and that they opposed McCain's amendment.

White House budget director Peter Orszag told reporters on Wednesday that Democratic proposals working their way through Congress could use "further tweaking" to strengthen them and further reduce the cost of U.S. healthcare. He declined to mention specifics. [ID:nN02462566]

The Senate plan is designed to slow the rate of growth in healthcare, expand coverage to about 30 million uninsured Americans and halt industry practices such as denying coverage to those with pre-existing medical conditions.

The bill would require everyone to have insurance, provide federal subsidies to help them pay for it and establish a new government-run insurance option to compete with private industry.

Democratic procedural options are limited by Senate rules designed to protect the rights of the minority and most agreements require unanimous consent. While Democratic leaders were trying to break the logjam on the Senate floor, they worked behind closed doors to address concerns about the bill among party moderates.

Democrats control exactly 60 votes in the Senate, and a number of moderate Democrats object to some of the provisions in the bill. Keeping the fragile coalition together on a series of procedural votes would be difficult.

"You put your head down and press ahead and use the rules of the Senate and procedures to get it done," Democratic Senator Bill Nelson said of Democratic plans for the bill. (Editing by Peter Cooney) ((For more on the U.S. healthcare reform debate, click on [ID:nN20512341])) ((john.whitesides@thomsonreuters.com; +1 202-898-8300; Reuters Messaging: john.whitesides.reuters.com@reuters.net))