Sen. Mitt Romney (R., Utah) introduced a bill Wednesday that would make E-Verify permanent, and is a step toward making the program mandatory across the nation.

The Permanent E-Verify Act would "make the E-Verify program permanent by removing the termination provision that has required Congress to repeatedly act to extend the program," according to a press release from the senator's office. E-Verify allows employers to determine the eligibility of their employees to work in the United States. It is set to expire on Sept. 30 this year if no congressional action is taken.

"Last month, a record number of 144,000 illegal immigrants were apprehended at the southern border, marking the highest monthly amount in more than thirteen years," Romney said in the press release. "Congress needs to act now to address our illegal immigration crisis by closing legal loopholes and removing the magnets—like illegal employment—that drive illegal immigration."

E-Verify is mandatory for all federal employees and some federal contractors. Overall, about 14 percent of U.S. employers use E-Verify.

Jessica Vaughan, director of policy studies at the Center for Immigration Studies, told the Washington Free Beacon the bill is a "no-brainer for Congress to pass."

"E-Verify is one of the best tools available for employers to avoid hiring illegal workers. It works well, employers who use it overwhelmingly like it, and they deserve to know that the program is not ever going to expire because of Congressional dysfunction," Vaughan said. "Preventing illegal employment is the key to controlling illegal immigration, so E-Verify has to be made permanent, but it also should be mandatory for all employers. Many states have already required at least some employers to use it, and this will guarantee continuity for them. The Senate should pass this bill and then send it over to the House, and then if the Democrats don't pass it, they should have to explain to voters why they cannot take even this tiny baby step to help prevent illegal employment."

Rosemary Jenks, director of government relations at NumbersUSA, found it a "little bit disappointing" the bill only made E-Verify permanent and not mandatory, noting that "until you make it mandatory, the employers who want to follow the law will use it and the employers who want to profit from illegal labor will not, so you'll have an unfair competitive advantage for the lawbreakers."

Romney called on his colleagues in the Senate to work towards making E-Verify mandatory.

"I urge my colleagues to take action on this important legislation to make E-Verify permanent, and continue working on long term fixes to secure our border, update our asylum and trafficking laws, and institute mandatory E-Verify nationwide," he said.