A new Maryland bill that would allow illegal immigrants to have driver's licenses is expected to go to referendum, with top Maryland officials saying it faces a real threat of being overturned by voters.

"I think the bill most difficult on the referendum would be the illegal driver's licenses. People go with their gut, they say 'why' and the problem is, they're here now," said Senate President Thomas V. Mike Miller Jr., D-Prince George's and Calvert counties. Miller voted in favor of the bill, which is awaiting Gov. Martin O'Malley's signature.

"It's easy to vote no, they're illegal -- boom. But if you explain it in paragraphs why it's the responsible thing to do, it passes," Miller said.

Del. Neil Parrott, R-Washington County, who heads MDPetitions.com, said his group isn't certain which new laws they will push to referendum, but internal Web and mail polling of the site's members shows interest in putting illegal immigrant driver's licenses on the ballot.

His group was successful in helping to get three newly passed bills onto the ballot last year -- same-sex marriage, redistricting and the Dream Act allowing some illegal immigrants to pay in-state college tuition. However, all of those were upheld by voters.

Parrott said MDPetitions.com is looking for organizations to partner with to campaign on the referendums leading up to the 2014 election, and will make an announcement next week.

"Last time the opposition was able to totally change the debate and get out their own information without any correction or data from our side because we were overwhelmingly underfunded," he said. "That can't happen again this time."

The bill would allow illegal immigrants to obtain a driver's license if they prove they have been paying income taxes in Maryland for the last two years. It would state that the license could not be used for federal purposes -- such as going through airport security -- and could not be used to buy a firearm.

Proponents say the measure would make the roads safer by requiring illegal immigrants to prove they know how to drive before getting behind the wheel and allow them to buy insurance. Opponents say it would incentivize illegal immigration and make Maryland a haven for those who entered the country illegally.

Illegal immigrants who live in Maryland wouldn't have to worry about crossing into Virginia. A spokeswoman for the Virginia State Police said they would honor any driver's license that is valid in the state it is issued.