WASHINGTON - The comprehensive immigration proposal being fashioned in the U.S. Senate may give new opportunity for H-1B critics to try to impose new restrictions on the visa. Then again, it may not.

The situation is murky.

The Senators who developed the chamber's latest comprehensive immigration effort outlined their framework at a press conference Monday, but offered few details about how their plan would actually work or what will be included in their bill.

A leading critic of the H-1B visa, Sen. Dick Durbin (D-Ill), one of the eight senators drafting the comprehensive plan, said he didn't know whether the H-1B visa will be included in the bill.

Durbin, along with Sen. Chuck Grassley (R-Iowa), have sought a number of restrictions on temporary worker visas.

The pair has offered bills in previous Congressional sessions that include a so-called 50/50 provision that would limit the number of visas available to a company to half of its workforce. Indian outsourcing firms are especially concerned about a 50/50-like provision in an immigration bill.

Durbin, meeting with reporters in a hallway after the press conference, said that if the H-1B visa is taken up as part of comprehensive reform, "I would certainly want to sit down with Chuck and offer this (Durbin and Grassley's previous bill) as an amendment because I think what we're doing there is reasonable."

Durbin said that he and Grassley want provisions that would "give Americans the first chance for the job."

The debate over the H-1B and STEM green card is embroiled in details.

Questions about prevailing wage levels, preference for U.S. workers in hiring, and limits on the number of any H-1B visas a company may use as well as the overall cap number would be critical issues in any immigration bill.

"We are only a part of the way done -- there are loads of pitfalls," said Sen. Chuck Schumer (D-N.Y.), at the press conference, of the comprehensive effort.

Schumer, Sen. John McCain (R-Ariz.) and some of the other senators speaking today said little about how their efforts at reform could impact technology companies.

The framework released Monday explicitly calls for green cards for advanced degree graduates of U.S. universities, but doesn't mention the H-1B visa at all.

Sen. Marco Rubio, who is part of the Schumer-led bipartisan group on immigration reform, is one of the senators behind an effort to raise the H-1B cap to a minimum of 115,000. Under an escalator clause, the cap could reach 300,000.

Rubio was asked at the press conference how his tech immigration proposal squares with the comprehensive effort.

Rubio's yet-to-be introduced bill includes a green card STEM visa plan similar to what the comprehensive framework calls for.

"Let's be clear this is outline of principals," said Rubio, the details yet to be crafted. "The principals quite frankly are very similar if not the same," in the comprehensive framework to the bill he is part of.

Patrick Thibodeau covers SaaS and enterprise applications, outsourcing, government IT policies, data centers and IT workforce issues for Computerworld. Follow Patrick on Twitter at @DCgov, or subscribe to Patrick's RSS feed . His e-mail address is pthibodeau@computerworld.com.