The Senate Judiciary Committee will not likely mark up a comprehensive immigration overhaul package until May because the bipartisan Senate group working on drafting a bill has taken longer than expected, Chairman Patrick J. Leahy said.

“For months I have urged the president to send his proposal for comprehensive immigration reform to the Senate,” the Vermont Democrat said in opening statement placed in the record during a committee immigration hearing today.

“I understand he has delayed releasing it at the request of a few Senators who are engaged in secret, closed door discussions on their own proposal and who committed to completing it by the beginning of March,” Leahy said. “That deadline and others have come and gone.”

President Barack Obama, however, has said he will not let Senate talks languish and could send up his bill to spur action.

The bipartisan group of eight senators released a framework for legislation in late January that includes providing a path to citizenship, revamping the existing immigration system, reducing the hiring of undocumented workers and creating a guest-worker program.

The group had sought to translate the framework into legislation by March, but the deadline slipped away as it wrestled with complications and waited for the U.S. Chamber of Commerce to negotiate with labor over guest-worker issues. The group now hopes to unveil its bill soon in April after the spring recess, but that could slip to mid-April, sources have said.

“Because we do not yet have legislative language to debate, the Senate Judiciary Committee will not be able to report a comprehensive immigration bill by the end of April, which was my goal,” Leahy said.

“The upcoming recess period would have allowed all Members of the Committee and the American people to review the legislation. Now that process and our work will be delayed at least a month,” Leahy continued.

Leahy also had hoped to broaden the discussion to those on the committee, which has jurisdiction over the nation’s immigration policy, because so far only the eight senators have been privy to the negotiations, and only some of them sit on Judiciary. Leahy also warned that it would take time to consider the bill, which is why the delay in drafting it makes the task that more difficult.

“I have favored an open and transparent process during which all 18 Senators serving on the Senate Judiciary Committee will have the opportunity to participate and to propose or oppose ideas for reform,” Leahy said. “The Majority Leader has agreed that we need regular order in the consideration of comprehensive immigration reform. This process will take time. It will not be easy. There will be strongly-held, differing points of view.”

Leahy’s comments come the day after six Republican Judiciary members, including ranking member Sen. Charles E. Grassley, R-Iowa, cautioned Leahy against rushing the bill through committee.

Leahy welcomed recent GOP support for comprehensive reform — which includes Sen. Rand Paul of Kentucky — but noted that Republicans helped defeat previous efforts.

“After slamming the door on our efforts for comprehensive immigration reform during the Bush administration, I welcome Republicans to this effort. While I still worry that too many continue to oppose a straightforward pathway to citizenship, that is a discussion we need to have out in the open, in front of the American people,” Leahy said.

Meanwhile, gang of eight member Sen. Jeff Flake, R-Ariz., said Wednesday that the group is “moving as fast as we can” to draft legislation based on its framework.

David Harrison contributed to this report.