The Biden administration’s plan to combine aid to Israel and Ukraine in one bill is encountering a surge of opposition from Republicans on Capitol Hill, where opposition to more aid for Ukraine has gained momentum in recent months. 

Last week, President Biden called on Congress to pass a $106 billion package that includes military aid to Ukraine and Israel; humanitarian aid to Gaza, Israel, and Ukraine; and new funding aimed at bolstering security at America’s southern border, as well as aid for Taiwan.

“Hamas and [President] Putin represent different threats. But they share this in common: They both want to completely annihilate a neighboring democracy,” Mr. Biden said.

The Senate majority leader, Charles Schumer, promised to pass the bill as quickly as possible, saying, “I have been working with the administration to ensure Israel has the tools it needs to defend itself.”

“This legislation is too important to wait for the House to settle their chaos,” Mr. Schumer said, referring to House Republicans’ struggle to elect a new speaker. “Senate Democrats will move expeditiously on this request, and we hope that our Republican colleagues across the aisle will join us to pass this much-needed funding.”

Senator McConnell threw his support behind the package in an interview with CBS’s “Face the Nation” Sunday, saying, “I know there are some Republicans in the Senate, and maybe more in the House, saying Ukraine is somehow different. I view it as all interconnected.”

Yet some Republicans in the Senate and many more in the House are opposing joining aid to Israel and Ukraine in a single package. Their opposition is grounded in concerns about sending more aid to Ukraine.

Over the weekend, Senator Vance circulated a memo to his colleagues arguing that linking aid to Ukraine and Israel “is a grave error that betrays a lack of strategic focus.”

In his memo, the Ohio freshman Republican lays out three arguments for not linking the aid. The first is that “Israeli operations will help secure the Gaza Strip; the Ukraine war has jeopardized the European security architecture and threatens global disorder.”

Mr. Vance also wrote that Israel is and has been “one of the cornerstones of U.S. foreign and security policy,” while Ukraine “is far from a strong partner” and that “Israel has an achievable objective; Ukraine does not.”

Mr. Vance’s final argument is that aid to Israel would likely “be specific, targeted to essential military systems to support a capable, well-trained, well-disciplined military,” while American aid to Ukraine “is neither well-scoped nor secure.”

In the House, opposition to linking aid to Ukraine and Israel will likely face far steeper opposition as candidates for the speakership begin announcing their opposition to the idea. The House must elect a new speaker before the body can even consider the issue.

In comments to CNN, Congressman Dan Meuser expressed his opposition to linking the aid packages, responding when asked whether he thought it was a good idea, “Absolutely not.” He added, “I think it’s wrong. We need to make bills simpler.”

Another candidate for speaker, Congressman Byron Donalds, has also staked out a position in opposition to linking aid to Israel with Ukraine or border security, citing a desire to put conditions on any new aid to Ukraine.

Congressman Kevin Hern, who is a speaker candidate as well, has also said that he is opposed to linking the two due to the fact that Republicans are divided on supporting Ukraine while united on Israel.

“We would split off Israel right now and get that passed because it would pass unanimously,” Mr. Hern told CNN. “We know there is some consternation around Ukraine. All we have asked the President to do is just tell us where the money is going.”

The issue has also made its way into Republican presidential politics, with businessman Vivek Ramaswamy saying that he opposes the idea of a combined aid package. “They’re intentionally combining the debates around Ukraine, Israel, and our border to ram through the $61BN for Ukraine that otherwise would have never passed,” Mr. Ramaswamy said. “Clear answer: vote NO.”