A new report reveals if Congress does not act to overhaul the country’s immigration system, the future could be bleak for businesses who depend on lower-skilled workers.

The study, which was released during a Capitol Hill meeting co-hosted by the Partnership for a New American Economy, a bipartisan group of mayors and business leaders, and the U.S. Chamber of Commerce, finds that while there is still a strong demand for low-skilled workers, the number of Americans willing to fill those low-skill jobs has dwindled dramatically during the last two decades.

The report is yet another signal that the business community is not giving up on its push to get immigration reform moving again on Capitol Hill. Even as Republican leaders have signaled 2014 is not the right time, groups like the Chamber are not backing down.

The study gets to the core of what the business community has been arguing for some time: employers need Congress to pass immigration reform in order to give businesses the access to the workers they need. According to the study, factors like lower birth rates and access to more educational opportunities in the U.S. have created an environment where immigrants are not just helpful to boosting the economy, they are essential to filling in the gap left by American workers who don’t want to take jobs as dishwashers, waiters, hospitality and field workers.

The number of jobs available to low-skilled workers has held steady during the last 20 years, but the number of less-skilled Americans between the ages of 25 and 44 who are a match for those jobs has dropped by more than 12 million.

“The time has come for Congress to act,” Randy Johnson, senior vice president of Labor, Immigration and Employee Benefits for the U.S. Chamber, said in a release. “Immigration reform would create a means to bring in more workers to carry the load created by demographic realities.”

Immigration Cartoons View All 171 Images

The report also notes that the demand for low-skilled workers is also expected to grow, which could cause even more of a crisis for businesses down the line.

“This decline in the number of less-skilled workers represents a real and growing threat to U.S. economic growth,” the report said.

The release of the study - which was authored by researchers at the University of California, Irvine and Temple University - comes at a time when there is little appetite among Republicans in the House of Representatives to tackle immigration reform in an election year. Even as pressure mounts from the business community, Republican leaders have yet to bring a string of comprehensive immigration bills to the floor for a vote.

The Chamber, which helped craft the Senate’s bipartisan immigration bill in 2013, has traditionally supported more Republicans than Democrats in elections and has hoped its pleas would get Republicans motivated to move on immigration reform.

In the beginning of the year, Chamber President Tom Donohue vowed to “pull out all the stops” to ensure immigration reform passed in 2014. In a letter to House Speaker John Boehner, R-Ohio, the 636 businesses affiliated with the chamber wrote that failing to pass immigration reform “was not an option.”

However, the Chamber, which has also made it a mission to push back against the tea party in the 2014 election cycle and support establishment candidates, is still pouring money behind lawmakers who have opposed immigration reform before. The group has spent $2.6 million on independent expenditures this election cycle and more than $500,000 was doled out to support Sen. Mitch McConnell, R-Ky., who opposed the Senate’s comprehensive immigration bill last year.

When asked about future campaign spending plans, the Chamber says it looks at a wide range of issues when deciding who it should support.