Language that could allow millions of immigrants to apply for a green card without most of the new border measures in place.

A Senate Republican amendment to the immigration bill that calls for tougher border security includes language that could allow millions of immigrants to apply for a green card without most of the new enforcement measures in place.

According to the new language, if legal challenges delay implementation of some of the border measures, immigrants with provisional status could start applying for green cards after 10 years. 

Supporters of the plan are downplaying the chances that legal hurdles would be in the way of implementing the border measures after 10 years. 

Opponents though say it presents a possibility that can't be ignored. Critics also note language allowing the government to almost immediately begin processing applications by illegal immigrants for provisional status, the first step toward getting a green card.

Sen. Jeff SessionsJefferson (Jeff) Beauregard SessionsIntel leaders: Collusion still open part of investigation Republicans jockey for position on immigration Biden to Alabama: No more extremist senators MORE (R-Ala.), a vocal opponent of the immigration bill, said the combined provisions will continue to lead to an onslaught of illegal immigration. He said that while the promise of enforcement is still years down the road, illegal immigrants have immediate opportunities to improve their legal status in the United States.

The new amendment "keeps the core amnesty-first framework of the bill," Sessions said Friday. "The day it passes immigration enforcement effectively comes to a halt."

The amendment from Sens. Bob CorkerRobert (Bob) Phillips CorkerDeficit hawks voice worry over direction of tax plan The Hill Interview: Budget Chair Black sticks around for now Overnight Finance: White House requests B for disaster relief | Ex-Equifax chief grilled over stock sales | House panel approves B for border wall | Tax plan puts swing-state Republicans in tough spot MORE (R-Tenn.) and John HoevenJohn Henry HoevenThe Hill's Whip List: Republicans try again on ObamaCare repeal Air Force One is Trump’s new boardroom Overnight Finance: Trump strikes debt, spending deal with Dems | Deal shocks GOP | Fed’s No. 2 to resign | Trump keeps tax squeeze on red state Dems | House aims to pass budget next week MORE (R-N.D.) does require five new border requirements to be in place before immigrants with provisional residency status could be given a green card.

Those requirements are submission of a border security plan and its deployment, installing at least 700 miles of border fencing, mandated use of an employment verification system, use of an electronic exit system at the border, and having at least 38,405 border agents in place.

The bill says that six months after the government certifies that these steps are in place, it can start issuing green cards to provisional residents.

But this language is followed by a key exception that would allow immigrants to start applying for these green cards, potentially with none of these measures in place.

The exception language says the government can allow provisional immigrants to apply for a green card if litigation has prevented any of the requirements -- except the new border agents -- or if implementation of these requirements has been found unconstitutional. To use either exception, 10 years must have elapsed since the bill became law.

The bill makes no mention of whether or when the government would ever be able to process applications sent in under that exception. But opponents of the bill argue that the language foresees the possibility of lengthy legal battles over the bill that would delay border implementation, which they say will only spur more illegal immigration given the easy access to improved legal status.

Critics of the Corker-Hoeven language also charge that it appears weak on the issue of dealing with immigrants who overstay their visas.

Corker said on Friday that the bill mandates "the initiation of removal proceedings for at least 90 percent of visa overstays."

Opponents though say the language in the amendment appears to give the government options other than removing immigrants, which would fall short of the 90 percent threshold.

The bill says 180 days after passage, the government "shall initiate removal proceedings… confirm that immigration relief or protection has been granted or is pending, or otherwise close 90 percent of the cases" involving visa over-stays.

This post was updated at 10:35 p.m.