In the latest roadblock to passing gun legislation, three Republican senators have threatened to filibuster next month's proceedings on the gun debate.

In a letter sent to Senate Majority Leader Harry Reid, Sens. Ted Cruz, R-Texas, Mike Lee, R-Utah, and Rand Paul, R-Ky., warned that they might filibuster any legislation that restricts gun rights.

"We, the undersigned, intend to oppose any legislation that infringe on the American people's constitutional right to bear arms, or on their ability to exercise this right without being subjected to government surveillance," the senators wrote in the signed letter obtained by ABC News. "We will oppose the motion to proceed to any legislation that will serve as a vehicle for any additional gun restrictions."

Reid announced last week plans for the Senate to consider a comprehensive gun package after the holiday recess. The bill would try to crack down on gun trafficking and include a requirement for universal background checks, a component opposed by many Republicans and moderate Democrats.

While the assault-weapons ban is not part of the comprehensive gun package that will be considered next month, Reid will allow a vote on the plan by amendment, a vote the White House has urged Congress to make in recent days but will likely be heavily opposed by Republicans.

Earlier this month, Paul led a 13-hour filibuster over drones. Cruz sits on the Senate Judiciary Committee and was part of the contentious debate on each gun proposal that was considered in committee earlier this month.