Republicans are warning that any meddling by the White House and House Democratic leaders could jeopardize prospects for congressional action on immigration reform.

The House immigration working group was on the cusp of a bipartisan deal, Politico reported, when House Democratic leaders pulled the plug due to opposition to a provision that would require immigrants to maintain private health insurance while waiting to get citizenship -- a process that could take up to 15 years. The provision is intended to prevent immigrants from accessing taxpayer-financed health care until they are citizens.

This has left the House working group's negotiations "hanging by a thread," said a source familiar with the talks. The impasse threatens any hopes for passing comprehensive immigration reform given that House Republicans are unlikely to accept the Senate version of the bill, the source said.

"They think that if they kill the House bill, the House will have to take up the Senate bill," this source said, expressing what Republicans believe is behind the Democrats' eleventh hour wrangling.

Rep. Xavier Becerra, D-Calif., a member of the House immigration group, has voiced this opposition on behalf of House Minority Leader Nancy Pelosi, D-Calif. The White House, meanwhile, has been quietly pushing back against Republican attempts to increase the number of visas granted to low-skilled guest workers, who would be allowed into the U.S. under the immigration overhaul. Republican sources charge that the White House is acting on behalf of organized labor.

"We're hoping we can do something as quickly as possible. We've been saying that for a little while, but I think it's because we realize how close we are," Becerra said this week during a news conference, projecting public optimism that a deal may remain in reach.

Sources familiar with the House immigration working group's talks, and specifically the position of its four Republican members, caution that the GOP lawmakers are growing "frustrated," particularly because the back-peddling by Democrats came after an agreement was reached in principle. In other words, Republicans say, Becerra and the other Democrats in the group were fine with the health care component of the deal until Pelosi protested.

The White House injecting itself into the process only adds to the tension, multiple GOP sources contend.

These sources warn that Democrats and President Obama should disabuse themselves of the notion that killing a House compromise will shift the debate in favor of the Senate bill as the primary vehicle for immigration reform. The best hope for moving immigration reform through the Republican House, they argue, is for the House to approve a comprehensive bill of its own before negotiating a comprise with the Senate in a conference committee.