All the members of the bipartisan “Gang of Eight” pushing immigration reform in the U.S. Senate will band together to block any efforts by other senators to offer amendments to their legislation once it is introduced, the Washington Post reported on Sunday.

“A bipartisan Senate group on immigration legislation is attempting to craft an agreement so secure that the eight members will oppose amendments to its core provisions, an arrangement that could delay the introduction of a bill, people familiar with the negotiations said,” the Post‘s David Nakamura wrote.

In response to Nakamura’s article on Monday, Gang of Eight member Sen. Marco Rubio’s spokesman Alex Conant told Breitbart News that his description of the process being worked on is not correct. “The legislation that the eight senators are working on is only the start of the process; we expect several committee hearings, a full debate, and an open process for other senators to offer amendments,” Conant said. “It’s premature to speculate about what sort of amendments might be offered, but if another senator offers an amendment that improves the legislation consistent with the principles Senator Rubio has outlined, then I would expect members of the group of eight to support it.”

But Rubio’s words are unlikely to do much to assuage the concerns of conservative Republicans in Congress, especially as fellow Gang of Eight member New York Democratic Sen. Chuck Schumer, Senate Judiciary Committee chairman Sen. Pat Leahy, and other Democrats appear poised to rush whatever bill the bipartisan group comes up with through as fast as they can once the legislative text is presented.

Nakamura notes the bill is expected to be around 1,500 pages long, and that the Gang of Eight “is trying to strike a deal in which all the members agree to oppose any amendments to the core provisions, even if they might agree with the amendments, people familiar with the talks said.”

“The group is concerned that if one provision is amended, the entire bill will fall apart because the deal is predicated on a comprehensive plan composed of carefully negotiated pieces,” Nakamura wrote.

This apparent effort by Gang of Eight members to force a deal through with no amendments and without a transparent process complete with public hearings examining the different facets of a forthcoming bill has worried conservatives on the Senate Judiciary Committee. The committee’s ranking GOP member, Sen. Chuck Grassley, and his colleagues Sens. Jeff Sessions, Ted Cruz, and Mike Lee recently wrote to all the Republicans in the Gang of Eight asking them to fight for a transparent process and hearings to examine each part of the coming bill, which still has not been written.

Sens. Jeff Flake, Lindsey Graham, and John McCain have not backed the efforts for transparency in this process. Rubio says he does back the efforts for a transparent process, and wrote back to those conservatives on the Senate Judiciary Committee to say that he views the Gang of Eight’s forthcoming legislative text as nothing more than a “starting point” from which other senators will be allowed to offer their input via amendments and hearings and other processes. But Leahy, the chairman of the Senate Judiciary Committee, has only said he will “consider” having just one hearing on the massive legislative package, and would not commit to a transparent process.