Senate Majority Leader Harry Reid (D–Nev.) is facing a revolt among Republicans for adding controversial language to an aid package for Ukraine.

The Senate is expected to vote on the Ukraine measure next week. The controversial provisions, which have support of the Obama administration and liberals from both parties, would increase U.S. financial support to the International Monetary Fund.

A growing number of Republicans warn that attaching the IMF language would reduce U.S. power while expanding Russia’s influence on the global stage in the wake of its annexation of Crimea.

>>> Q&A: Why Do Conservatives Oppose the IMF Reform Package?

Yesterday, Sen. Ted Cruz (R–Texas) spearheaded a letter of opposition backed by four other senators: Mike Enzi (R–Wyo.), Mike Lee (R–Utah), Rand Paul (R–Ky.), and Pat Roberts (R–Kan.). In their letter to Reid, they wrote:

We are deeply concerned that the Ukraine aid legislation reported by the Senate Foreign Relations Committee contains “reform” provisions that would unnecessarily double the United States contribution to the International Monetary Fund (IMF), part of the largest proportional increase ever, yet ultimately undermine our influence in that body in a manner that provides no actual relief to Ukraine.

As we understand it, this reform would double the funds the IMF can loan, involving a doubling of the United States’ contribution from its current level of $63 billion, while simultaneously reducing U.S. influence over how these funds are directed—and increasing that of Russia. Regardless of the magnitude of this change, this idea is antithetical to the driving purpose of the underlying legislation.

The five Republican senators asked Reid to allow a vote to strip out the IMF language.

Heritage’s Jim Roberts, a research fellow for economic freedom and growth, has warned that inclusion of the IMF language in the Senate bill exploits the Ukraine aid package.

“The actions by the Obama Administration and the U.S. Senate to connect these unrelated issues in one piece of legislation represents a corruption of the congressional process, and that legislative body’s failure to deal with the Ukraine issue on its own merits,” Roberts said.

The IMF provisions were first proposed in 2010. Among the changes, Roberts noted, are the loss of U.S. veto authority over IMF funds and less control over the IMF’s decisions.

“Incredibly,” Roberts warned, “the reform package would also increase Russia’s power at the IMF at the very time when the U.S. is seeking to punish Russia for its act of war and aggression in Crimea.”