Updated

Organized labor and big business have reached a deal on a new, low-skilled workers program that will help clear the way for Capitol Hill immigration reform, but President Obama and a leading Republican senator maintain cautious optimism about a final deal.

The deal was reached during a Friday night phone call between AFL-CIO President Richard Trumka and U.S. Chamber of Commerce chief executive Tom Donohue, according to several news organizations and confirmed by Fox News.

The deal was brokered by New York Democratic Sen. Chuck Schumer, who also was on the phone call and is one of eight senators working on bipartisan reform legislation.

"This issue has always been the dealbreaker on immigration reform, but not this time," Schumer said.

"The strength of the consensus across America for just reform has afforded us the momentum needed to forge an agreement in principle to develop a new type of employer visa system," Trumka said in a statement late Saturday. "We expect that this new program, which benefits not just business, but everyone, will promote long overdue reforms by raising the bar for existing programs."

Despite the breakthrough, Florida Republican Sen. Marco Rubio’s office cautioned Saturday that Congress still has a long way to go before passing legislation in the Democrat-controlled Senate and the Republican-controlled House.

Rubio sent a letter Saturday to Judiciary Committee Chairman Patrick Leahy, D-Vt., calling for a deliberate hearing process on the new legislation and cautioning against a "rush to legislate."

“Senate negotiators are making good progress on immigration reform, but we're not done yet,” Rubio press secretary Alex Conant tweeted Saturday.

White House spokesman Clark Stevens said Obama continues to be encouraged by the progress being made by the bipartisan group of senators.

“We look forward to seeing language once it is introduced and expect legislation to move forward as soon as possible,” he said.

A source told The Associated Press, on the condition of anonymity, the deal resolves disagreements over wages for new, low-income workers and which industries would be included.

All members of the so-called Gang of Eight are expected to sign off on the agreement.

The remaining big hurdles to passage are securing the U.S. borders, cracking down on employers who hire illegally and creating a pathway to citizenship for 11 million illegal immigrants already in the country.

The bipartisan group is expected to introduce the bill officially the week of April 8, after Congress returns from a two-week recess.

The AFL-CIO and the Chamber had been fighting over wages for tens of thousands of low-skilled workers who would be brought in under the new program to fill jobs in construction, hotels and resorts, nursing homes and restaurants and other industries.

On Friday, officials from both sides said there was basic agreement on the wage issue, and Schumer said a final deal on the worker dispute was very close.

"We're feeling very optimistic on immigration: Aspiring Americans will receive the road map to citizenship they deserve and we can modernize `future flow' without reducing wages for any local workers, regardless of what papers they carry," AFL-CIO spokesman Jeff Hauser said in a statement earlier this week. "Future flow" refers to future arrivals of legal immigrants.

Under the emerging agreement between business and labor, a new "W" visa program would bring tens of thousands of lower-skilled workers a year to the country. The program would be capped at 200,000 a year, but the number of visas would fluctuate, depending on unemployment rates, job openings, employer demand and data collected by a new federal bureau pushed by the labor movement as an objective monitor of the market.

The workers would be able to change jobs and could seek permanent residency. Under current temporary worker programs, personnel can't move from employer to employer and have no path to permanent U.S. residence and citizenship. And currently there's no good way for employers to bring many low-skilled workers to the U.S. An existing visa program for low-wage nonagricultural workers is capped at 66,000 per year and is supposed to apply only to seasonal or temporary jobs.

The Chamber of Commerce said workers would earn actual wages paid to American workers or the prevailing wages for the industry they're working in, whichever is higher. The Labor Department determines prevailing wage based on customary rates in specific localities, so that it varies from city to city.

The low-skilled worker issue had loomed for weeks as perhaps the toughest matter to settle in months-long, closed-door talks on immigration among the senators, including Republicans John McCain, Arizona, and Rubio.

The issue helped sink the last major attempt at immigration overhaul in 2007, when the legislation foundered on the Senate floor after an amendment was added to end a temporary worker program after five years, threatening a key priority of the business community.

The amendment passed by just one vote, 49-48. Obama, a senator at the time, joined in the narrow majority voting to end the program after five years.

The president, who won roughly 71 percent of the Hispanic vote during his November re-election, has made immigration reform a key part of his second term. And Republicans are attempting to improve their relationship with Hispanics, the fasting growing segment of the U.S. populations.

The Associated Press contributed to this report.