Senate Democrats on Wednesday unveiled a sweeping Russia sanctions package they hope will deter Russian President Vladimir Putin from invading Ukraine with the massive number of troops he has amassed along its borders.

However, the lack of any Republican co-sponsors to the bill from Senate Foreign Relations Chairman Bob Menendez raises serious questions about its future in the sharply divided Senate.

With the chamber slated to vote this week on an alternative bill from Sen. Ted Cruz, R-Texas, that would within two weeks of enactment impose sanctions on foreign business officials assisting in the finalization of the Russian-German Nord Stream 2 natural gas pipeline, it could be that some otherwise interested GOP senators are withholding their co-sponsorship from the Menendez legislation until after that vote.

Publicly, Republicans continue to insist the Nord Stream 2 bill, which would primarily impact European officials, is the right approach to take in sending a tough message to the Kremlin — while also protecting Ukraine from Putin’s ability to use the pipeline as a form of diplomatic energy blackmail against it and other European importers.

The Biden administration and many Democrats oppose the Cruz sanctions measure. They argue it weakens leverage over Russia and is needlessly divisive toward Germany at a time when Berlin’s support is seen as key in presenting a united transatlantic front in talks with Moscow. The White House and Democrats also argue it is unhelpful in constructing a multilateral response with European partners to any possible Russian aggression against Ukraine.

“Where Nord Stream 2 is concerned, we’ve been clear about our position,” Deputy Secretary of State Wendy Sherman said at a Wednesday press conference in Brussels, where she was meeting with NATO partners about the Ukraine crisis. “It is a Russian geopolitical project that undermines energy security and the national security of a significant part of the Euro-Atlantic community.”

Sherman noted Berlin has suspended work on the pipeline’s certification and there has been “quite a consistent assessment” from Washington and its allies that the pipeline will not become operational if Russia invades Ukraine.

At least 10 Democratic supporting votes would be needed for the Cruz measure to pass the Senate. Sen. Rand Paul, R-Ky., has also spoken critically of the sanctions approach taken by the legislation.

“I’ve asked the sponsors of the bill what their strategy is, what is the behavioral change you would like on the part of Russia or Germany? And they said, ‘We just don’t want the pipeline. We don’t want them … to sell natural gas to each other,’” Paul said Wednesday at a Foreign Relations hearing. “Well, that’s not really a strategy that is achievable. … If we just say tomorrow, ‘We’re no longer going to let you sell gas between Russia and Germany,’ I don’t know what deterrence that effect has.”

But the new bill from Menendez and 25 Democratic co-sponsors, including Senate Majority Leader Charles E. Schumer of New York and Majority Whip Richard J. Durbin of Illinois, has some provisions that could tempt Republican support. But that largely depends on fallout from the vote on Nord Stream 2 sanctions.

The Democratic bill would put in place a comprehensive mandatory sanctions regime against Russia’s top political and military leaders, banks, and its oil, coal and gas sectors, which would be immediately triggered if Russia attacks Ukraine.

The legislation would mandate personal sanctions on Putin and top members of his cabinet and the Russian military leadership. It would also order the sanctioning of at least three of Russia’s largest financial institutions and would ban direct and secondary transactions involving the purchase of Russian sovereign debt.

The legislation would further authorize steps to cut Russian banks off from the SWIFT financial payments system, which processes quick and secure cross-border transactions at over 1,100 major banks around the world.

Additionally, the measure authorizes $500 million in additional emergency security assistance to Ukraine if there is a Russian invasion.

“We are coming together to send a clear message — Putin need not collapse his entire economy nor does he need to sacrifice the lives of his own people in a futile attempt to rewrite the map of Europe,” Menendez said in a statement. “I look forward to working with my Democratic and Republican colleagues so that we can provide the people of Ukraine the type of support they need to confront the bully in Moscow.”