Business and labor negotiators working on a comprehensive immigration overhaul package are almost ready to announce an agreement on a guest worker program, a significant hurdle that could clear the way for a much-anticipated bipartisan bill to be revealed the week of April 8.

“We are very close, closer than we have ever been, and we are very optimistic, but there are still a few issues remaining,” Sen. Charles E. Schumer, D-N.Y., said of a potential guest worker deal. Schumer is one of a bipartisan group of eight senators working on bill.

Sources familiar with negotiations said it’s a matter of finalizing the details on the guest worker program, which would provide visas to immigrants to work at low-skilled jobs.

Under the expected agreement, there would be a maximum of 200,000 visas available, and the figure would only rise to that level depending on economic need. The anticipated proposal is also expected to require employers to pay the same to guest workers as they typically pay their regular workers doing the same job, or the prevailing wage, whichever is higher.

These had been sticking points in talks being held AFL-CIO officials and the U.S. Chamber of Commerce, who were charged by the eight senators to work out a plan.

“We’re optimistic,” said AFL-CIO spokesman Jeff Hauser.

Randy Johnson, the chamber’s senior vice president of Labor, Immigration, and Employee Benefits, did not deny that talks were closing in on an agreement.

“Ultimately, the final decisions will be made by the senators involved,” he noted.

Reaching an agreement could go a long way toward getting a bill into legislative language, sources said.

“It’s a big step,” said one source, noting that once there is agreement, it can be put in to the draft bill.

Pressure has been mounting on the group of eight senators to unveil its bill. Senate Judiciary Chairman Patrick J. Leahy, D-Vt., has said he intends to take up the bill as soon as possible but has also expressed concern that the delay in unveiling a bill has made it difficult to clear the bill before the end of April. The “gang of eight,” which announced a legislative framework in January, had originally said it would unveil a bill in March.

President Barack Obama has also recently called on Congress to pick up the pace on immigration reform. Earlier this year, he said he would put out his own bill if the congressional process takes too long, but he also has said he expected the group of eight to deliver after the recess.

It is unclear if the group will announce an agreement on the guest worker program, if one is achieved, or whether it will wait to unveil the entire measure after the recess.

Some observers didn’t expect an announcement in part because of the Good Friday holiday, noting many people are off work. Also Sen. John McCain, R-Ariz., a member of the group, is traveling abroad.

However, the New York Times reported that a deal could be announced Friday.