Image credit: Charles Dharapak/AP Photo

With bipartisan discussions in the lower chamber seemingly on the brink of collapse, six Republican senators met with weary House conservatives this afternoon to discuss the prospects of immigration overhaul.

Sens. Marco Rubio and Jeff Flake - both members of the Senate's so-called Gang of Eight - joined Sens. Mike Lee, Ted Cruz, Rand Paul and Jeff Sessions to attend a meeting of the Republican Study Committee and debate the options ahead.

Rubio, viewed as a critical GOP vote necessary to pass a comprehensive law, has cautioned lawmakers that the Gang's proposal does not sufficiently address border security, damning the bill's prospects in both chambers of Congress.

"There's a vibrant debate going on in the Republican Party," Rubio, R-Fla., said. "I can tell you that the bill, as currently structured, isn't going to pass in the House, and I think it's going to struggle to pass in the Senate.

"Let's remember the goal here is not to pass a bill out of the Senate. The goal here is to reform our immigration laws and that requires something that could pass the House, the Senate, and be signed by the president."

Rubio said he believes Republicans are "generally prepared" to do immigration overhaul as long as Congress ensures that it doesn't cost the taxpayer money or lead to another wave of illegal immigration in the future. Senate conservatives, like Sen. Paul, have identified shortcomings in the legislation regarding border security, and stress that the Gang's blueprint does not adequately address a broken work visa system, either.

"I'm for immigration reform. I want to do something, but I want to do the right thing," Paul, R-Ky., told reporters as he arrived for the closed-door meeting. "Really you have to fix the system, and if you don't fix the work visa system, if you don't make it better, you're still going to have illegal immigration."

Asked how critical Rubio's support is to ensure the successful passage of a bill, Paul said the focus should be on reaching 60 votes, not winning the support of any individual. "I'm a possible yes vote, but the bill has to be better," he said. "If they don't have 60 votes, and they want me to vote for the bill, and they want immigration reform to proceed, if they're genuine in this and want the bill to be better, that's what I want. I want a stronger bill to work, I want a work visa program that allows people to come into our country to work basically."

Paul has introduced an amendment that would institute what the senator described as "trust but verify" triggers that require Congress to vote to deem the border secure each year.

"If we vote that the border is not becoming more secure, then what happens is the process stops until the border becomes secure," Paul said. "The main complaint of conservatives, myself included, is that there isn't a mechanism for making sure and ensuring that the border is secure."

The House's secret group had reached an agreement in principle last month, but that deal was apparently derailed when House Minority Leader Nancy Pelosi supposedly rejected it. A senior Democratic leadership aide, however, emphasized that the group was still meeting today, and added that reports that it is dissolving is an attempt at leverage by one of the group's members: Rep. Raul Labrador.

Rep. Raul Labrador, R-Idaho, "has repeatedly threatened to walk away as a negotiating tactic," the aide emailed. "Pelosi and House Democratic leaders have repeatedly played the role of cheerleading the bipartisan group along: expressing optimism and aggressive timelines for success."

While the group of lawmakers in the House working on the issue may be prepared to call it quits today, Rubio encouraged members to pursue stand-alone measures in order to advance an overhaul.

"I'm not in a position to tell the House what they can or should do," Rubio said. "This issue can be handled with separate bills but ultimately it must be handled comprehensively."