Sen. Peter Welch attends a Senate Judiciary Committee markup in Hart Building on Thursday, May 11.

Democrats in the Senate on Wednesday continue to debate whether more conditions need to be placed on aid sent to Israel, just one in a series of hurdles stalling a legislative package members in both chambers of Congress hope to send to aid Israel, Ukraine and the US southern border.

Democratic Sen. Peter Welch of Vermont, who has been outspoken in advocating for conditions to be placed on any aid to Israel, told CNN on Wednesday morning that he would not necessarily vote against an aid package if conditions were not included.

Pressed on if he’d still back aid to Israel without conditions, Welch told CNN: “We’re not at that point yet. So I’ve always supported Israel aid and I expect that I will, but I’m making my point of concern, very clear.”

Many Senate Democrats who are opposed to conditioning aid to Israel have argued that the administration is engaging already with Israel about how it conducts its military operations and that international laws already exist to govern the rules of war. Democrats met with IDF officials Monday night to discuss the issue as well.

Sen. Bernie Sanders, an independent from Vermont who has also been advocating for conditions on the aid, wouldn’t say Tuesday when pressed on if he’d vote against an aid package to Israel if more conditions were not included.

Conditions on the aid was the topic of a robust debate in Democratic lunch on Tuesday, members told CNN. But the chances of conditioning aid aren’t likely as top Democrats including Democratic Sen. Ben Cardin of Maryland, who chairs the Senate Foreign Relations Committee, have warned against it.

Republicans have outright rejected adding them including Senate Minority Leader Mitch McConnell of Kentucky. Senate Majority Leader Chuck Schumer dodged the question earlier this week when pressed by CNN’s Manu Raju.

Any package that passes the Senate would also have to get through the GOP-led House, which is also likely to reject conditions on the aid to Israel.

Democrats warn they are deeply worried about direction of border talks

To add to the legislative hurdles, a number of Senate Democrats warned the direction of ongoing border negotiations could imperil aid for Israel and Ukraine and say they do not support significant changes to the US asylum process, which they view as potential “poison pills.”

“I trust my Senate colleagues to negotiate in good faith, which is why changes to both asylum and parole could be possible, but it has to be done without the kind of draconian or drastic changes that will subvert the entire process,” Sen. Richard Blumenthal of Connecticut, told CNN. “Poison pills should have no part in aiding Ukraine or assisting Israel at a point where their survival and our national interests are vitally at stake.”

It’s the latest sign that Democratic support for any border proposal is far from guaranteed and reflects the tightrope Senate negotiators are walking to find a deal that doesn’t crater so much support on the left and right that it cannot pass at all, knowing that not addressing the issue in the Senate would mean the bill would face long odds in the House.

For weeks, a small group of senators including independent Kyrsten Sinema of Arizona, Democratic Sens. Chris Murphy of Connecticut and Michael Bennet of Colorado and Republican Sen. James Lankford of Oklahoma have been trying to chart a middle ground on the complex and politically perilous issue of immigration, in hopes of attaching it to a package sending aid to Israel and Ukraine. But in doing so, negotiators are finding themselves with little room to maneuver and with pressure mounting from outside groups.

Republicans are insisting that significant changes must be made to asylum policy and to the way the Biden administration handles so-called humanitarian parole. They are facing pressure from conservatives in their ranks, from outside groups and from conservatives in the House to push for robust policy changes that more closely reflect elements of the House-passed immigration bill.

“For me, this is a non-negotiable concept of major policy changes,” GOP Sen. Lindsey Graham of South Carolina said. “It doesn’t have to be everything I want, but it has to be major.”

Meanwhile, Democrats are also facing pushback from their base and outside immigration groups to not support a package that fundamentally overhauls how the country handles asylum claims and in their view would make it much harder to help immigrants who are feeling violence or threat of persecution.

The asylum piece of the negotiations had been a bright spot in the talks, multiple aides told CNN and a place where negotiators had made progress. Negotiators were looking to raise the credible fear standard in the initial interview for immigrants crossing the border who were seeking asylum. Republicans argue that doing so would curb the number of immigrants eligible to go through what is often a lengthy and drawn out process, which has created a massive backlog.

But, nearly a dozen Democratic senators released a statement Wednesday morning warning the floated changes were going too far – among them: Illinois Sen. Dick Durbin, the Democratic whip and chairman of the Senate Judiciary Committee.

“I’m very concerned about it. And we had what 10 or 11 of My colleagues who joined the letter that (California Democratic Sen. Alex) Padilla started,” Durbin said. “I want to see what’s going to happen here. I’ve talked directly to Sen. Murphy. And I said, ‘I hope this letter doesn’t put too much pressure on you.’ He said ‘I’m glad the Republicans know that we feel that strongly about the issue.’”

Murphy was deeply skeptical a deal can be reached this week — even though the group is trying to secure an accord that could pave the way for passage of the Ukraine and Israel aid.

Murphy had said earlier this week that the group needed to have a deal by week’s end in order to have time for Congress to consider the larger package before Christmas.

“I think it’s becoming less and less likely that we’ll have a deal by the end of the week,” Murphy told CNN on Wednesday.

Republican Sen. Thom Tillis of North Carolina, who has been involved in the talks, told CNN it’s up to both sides to live with the fact that a deal in the middle is going to attract arrows from all sides.

“The bipartisan agreements are always difficult because you got everybody mad at you,” Tillis said. “That’s what compromise is right? Nobody gets exactly what they want. So I’ll have my base mad at me. They’ll have their base mad at them.”

CNN’s Manu Raju, Morgan Rimmer and Lauren Koenig contributed to this report.