With negotiators making slow but steady progress in bipartisan talks on a comprehensive immigration bill, Senators might see the first detailed provisions of the emerging package as early as today, aides said Wednesday.

Thanks to a last-minute stay from Majority Leader Harry Reid (D-Nev.) late Tuesday night, Republicans and Democrats attempting to craft a deal with wide bipartisan support will have until Monday to come to an agreement. But while Reid put off his threat to move to last year’s version of the legislation, he said Wednesday that he remains skeptical a deal can be reached by Monday.

Despite some optimism Tuesday evening, which led to his decision to postpone the debate, Reid said Wednesday that “I don’t feel so strongly this morning. I got to the office with a number of phone calls from people from around the country disturbed with some things” in the compromise being work out. As a result, Reid gave a settlement a “50-50 chance” of being brokered.

Conservative Republicans struck a cautious tone following a midday meeting of the GOP Conference during which Conference Chairman Jon Kyl (Ariz.) outlined the deal so far. Sen. Mel Martinez (Fla.), a key Republican negotiator in the bipartisan talks, praised Kyl’s presentation, telling reporters that the meeting “went very well. I think Jon Kyl did a fantastic job of laying everything out.”

Sen. Johnny Isakson (R-Ga.) described the meeting as a “very thoughtful interchange … totally academic. It wasn’t political.” But he acknowledged that no specifics were discussed and said it remained to be seen whether conservatives in the Conference would ultimately be able to support any deal. “Hopefully [members will] get some information in the next 48 hours” on specific language, Isakson said.

Sen. John Thune (R-S.D.) agreed, saying that while “it’s moving in the right direction,” conservatives expressed “a lot of healthy skepticism” because few details have been released, and even those that have seem to shift. “Anytime they come out and say, ‘This is the deal,’ when they put it to writing the deal changes.”

Martinez and others involved in the talks said that while much of the deal continues to be in flux, it appears to be coming together. He said conservative stalwart Sen. John Cornyn (R-Texas) is “working on some issues that haven’t been resolved” and lawmakers have narrowed the list of problems which will remain outstanding once floor debate starts to “half a dozen or so.”

With many Senators expected to leave tonight for their home states, negotiators hope to have text of the deal prepared as soon as today for review. Aides and lawmakers said they hoped specifics would quell concerns among conservative Republicans. However, lawmakers said it was unclear whether they will be presented with actual bill language or a detailed summary.