Updated

They’re not the conservative faction that has been front and center in the opposition to giving undocumented immigrants a chance to legalize their status and stay and work in the United States.

The toughest stumbling block to a comprehensive immigration reform agreement in the House of Representatives, The Hill reports, may well be a quiet group – a handful of Tea Party conservatives who aren’t the kind of fixtures in front of the camera that other immigration hardliners, such as Rep. Steve King of Iowa and Rep. Louie Gomert of Texas, have been on the emotionally-charged issue.

Those quiet critical few, The Hill said, include Reps. Jason Chaffetz (Utah), Trey Gowdy (S.C.), Justin Amash (Mich.), Renee Ellmers (N.C.) and Steve Scalise (La.).

These lawmakers are likely to look to conservative peers – not lobby groups or the GOP establishment – for cues on how to move on the immigration issue, the publication said.

House Speaker John Boehner, an Ohio Republican, has said he will push a measure if it gets a majority – or 117 – of the 233 members of the Republican conference.

“American Principles [Project, dedicated to promoting conservative policies] is going after Tea Party conservatives who are influencers. Their votes will influence other Tea Party members and at the end of the day that will make the difference with House Republicans,” said Alfonso Aguilar, executive director of Latino Partnership for Conservative Principles, to The Hill.

Immigration reform seemed on a roll last year as a bipartisan group in the Senate worked very publicly on a comprehensive measure that ultimately called for beefing up border security, expanding foreign work visa programs, and providing a path to legal status for certain undocumented immigrants.

The Senate passed the bipartisan measure in June.

But almost immediately conservatives in the House, where Republicans have a majority, vowed not to rubber-stamp the Senate measure.

They said they would act on immigration in a piecemeal way. And some of the most conservative Republicans said they would not approve any measure that called for giving a break to people who had broken immigration laws.

And so, efforts to pass an immigration measure in the House came to a halt.

“Libertarians are more inclined to an open borders strategy,” said a GOP aide, who was not named in The Hill story.

Some of the country’s leading proponents who lobby for strict immigration enforcement concede that swaying lawmakers on immigration is a tough battle.

“It’s very difficult to change the minds of 180 people or 100 people so you look to see who the peer leaders are in each class and also state delegations,” said Roy Beck, executive director of NumbersUSA, which supports reduced immigration. “We certainly have anticipated the importance of keeping those kind of people on board.”

“Our activists are hitting (N.C. Rep. Renee) Ellmers very hard after her comments this week. If any of these type of people show signs of giving in to the establishment, we do regard it as very important,” he added.

Meanwhile, Republicans are said to be working on a set of “immigration principles” that call for stricter enforcement as well as allowing some undocumented immigrants to earn a legal status.

Some conservatives, including Sen. Jeff Sessions of Alabama, have strongly denounced the principles, though they have not been made public.

Sessions reportedly held a meeting with staff members of some conservatives last week to strategize about how to handle the principles and other developments regarding immigration reform.

He has warned that legalizing millions of immigrants and giving foreign nationals expanded opportunities to work in the United States will be detrimental to American workers.

“It would be tragic if the Leader's immigration principles were simply a ‘piecemeal’ repackaging of the Senate plan,” he said in a statement, The Hill reported.

On Tuesday, President Barack Obama is expected to push again for congressional action on immigration reform in his State of the Union address.

Follow us on twitter.com/foxnewslatino
Like us at facebook.com/foxnewslatino