Three Republican lawmakers are sponsoring ballot measure proposals to address illegal immigration in Oregon, riling Latino advocates and adding to a November 2016 ballot that could already end up heaped with contention.

Their three proposals would make English the state's official language, require people to provide proof of citizenship when registering to vote, and make employers verify workers' legal status.

They join other fractious ballot proposals, including to increase the minimum wage, raise corporate taxes and repeal Oregon's clean-fuels law.

The language measure would prohibit public employers from requiring workers to speak anything other than English. Exceptions would include language teachers, lawyers and medical workers. The measure would also require that state business be conducted in English. For the most part, it already is.

The voter registration proposal would make people present a passport, birth certificate or some other proof of citizenship to register.

The last measure would require businesses to use the federal E-Verify program to check whether prospective workers are in the country legally. Employers who don't could be banned from doing business in Oregon.

Supporters, riding on the coattails of Republican presidential campaigns that have focused heavily on immigration, plan to start collecting signatures once the final wording is set. They say the measures would deter undocumented immigrants from coming to Oregon.

"We have a culture in America that you must adjust to, and I feel like we should adjust to it," said Rep. Sal Esquivel, R-Medford, whose father emigrated from Mexico.

Esquivel is a chief petitioner of the English measure with Rep. Mike Nearman, R-Dallas, and Sen. Kim Thatcher, R-Keizer. Nearman and Esquivel are petitioners for the worker verification measure. Nearman is a petitioner for the voter registration proposal.

Immigrant rights groups, still stung by a failed 2014 ballot measure that would have enabled undocumented immigrants to get driver cards.

The measures, if passed, could have "potentially dangerous implications for the state," said Andrea Miller, executive director of Causa, an immigrant right group, is forming a coalition opposed to the measures.

Miller said the voter registration proposal would kill community registration drives. The language measure, she said, could make it harder for people who don't speak English to get information on government services, although the wording makes it hard to tell exactly what might change.

She said all three are hostile toward immigrants.

"Any law or policy that makes it difficult to learn, work and vote in Oregon is not a good policy," Miller said. "I believe all three of these ballot measures are directed as these growing communities in our state."

Oregon is becoming increasingly diverse. Latinos make up more than 12 percent of Oregon's population, up from 4 percent in 1990, according to the latest U.S. Census Bureau estimates. Asians make up 4 percent, up from 2 percent in 1990.

"We need to feel like Oregon is a welcoming and inclusive place," said Carmen Rubio, executive director of the Portland-based Latino Network. "These are anti-immigrant and voter oppression measures."

Nearman said the ballot measures aim to help immigrants, not hurt them.

"If you want to be successful in the United States, you pretty much have to speak English," Nearman said. "When we coddle people, we're not doing them any favors."

As for voter registration, Nearman said asking for proof of citizenship seems "pretty obvious." Under Oregon's new motor-voter law, people will be automatically registered when they get or renew their driver's license -- which requires providing proof of citizenship. But those who register by mail or online need only say they're U.S. citizens -- though lying is a felony.

There are questions about how the English language proposal would work.

Some 1,700 state workers receive additional pay for being bilingual, according to the Department of Administrative Services. More than half of those are in the Department of Human Services, where case workers provide services to people who don't speak English.

"There are federal requirements that we must provide reasonable accommodations to people who don't speak English or don't speak it well," said Matt Shelby, the Department of Administrative Services spokesman.

The ballot measure says the state can use foreign languages when not doing so violates federal law.

But proponents say everyone should learn English.

"They're dividing the fabric of the community by not learning to speak English," said Jim Ludwick, spokesman for Oregonians for Immigration Reform. "We're not discriminating against any particular group. We just feel learning English would be important if you want to become a citizen."

-- Ian K. Kullgren

503-294-4006; @IanKullgren