UPDATE (5:30pmET):

The House Rules Committee  plans to meet Thursday to consider repeal of the Obama health care plan. The rule to consider repeal of the health care law will be brought to the House floor Friday according to the committee. Fox confirms the vote to repeal the law will take place January 12th.

After indications over the weekend that Republicans are looking to vote on a repeal of health care legislation, five Democratic senators, including Majority Leader Harry Reid (D-NV), have written a letter warning incoming House Speaker John Boenher (R-OH) of the effects a health care repeal would have on seniors who fall into the so-called Medicare "donut hole," and vowing to block any Republican-led effort aimed at repealing the legislation.

Provisions of the new health care law that just took effect on January 1st give seniors a 50 percent break on the cost of prescription drugs when they're caught in a gap between basic and catastrophic Medicare coverage. The health care law is supposed to end the Medicare "donut hole" in the year 2020.

 But the Democrats who authored the letter say a repeal of the legislation-which House Republicans plan to make a priority when they take over the majority in the new session-would reopen the loophole, potentially costing seniors thousands of dollars in drug payments.

"The incoming House Republican majority that you lead has made the repeal of the federal health care law one of its chief goals," the letter to Boehner said. "We urge you to consider the unintended consequences that the law's repeal would have on a number of popular consumer protections that help middle class Americans."

Democrats will still maintain control of the Senate in the new Congress and the letter's authors vow to stop any attempt by House Republicans to repeal the health care law. Democrats Chuck Schumer (D-NY), Dick Durbin (D-IL), Patty Murray (D-WA), and Debbie Stabenow (D-MI) joined Reid in signing the letter.

"If House Republicans move forward with a repeal of the health care law that threatens consumer benefits like the "donut hole" fix, we will block it in the Senate. This proposal deserves a chance to work. It is too important to be treated as collateral damage in a partisan mission to repeal health care," the letter said.

Some Republicans have suggested a House vote to repeal the health care law could come before the president's State of the Union Address in a few weeks.

While some support cost-saving health care reforms, Republicans have used a potential repeal of the controversial health care legislation as a rallying cry since it was passed in March of 2010.

"House Republicans support common-sense health care reforms that lower cost - but such reforms do not require a trillion-dollar government takeover of health care that will raise costs, force millions of Americans to lose their current coverage, and destroy American jobs," Boehner spokesman Michael Steel told FOX.

The letter may be an early indication of tension that will exist between the Republican-controlled House and the Democratic-controlled Senate in the new Congress.