WASHINGTON - A dozen Republican senators joined together Wednesday to try to force action on a package of tough immigration measures, including one by Sen. John Barrasso, R-Wyo., to penalize states that issue driver's licenses to illegal immigrants.

The 15 separate bills would establish a mandatory minimum prison sentence for illegal immigrants, require English to be the national language and speed the building of a border fence in the Southwest, among other measures.

"It just makes sense to get some pieces in place, to help secure the borders and make sure that illegal immigrants don't get documents that they can use to then rent a car, get on an airplane," Barrasso said.

The dozen Republicans who introduced the bills said passing the individual measures would be easier than pushing a comprehensive immigration reform measure. Last year the Senate considered but failed to pass a major overhaul that most Democrats and the White House supported but many Republicans did not.

Sen. Jeff Sessions, R-Ala., led the effort to package the 15 bills. He said the sponsors will try to bring them up on the Senate floor, either directly or by attaching them as amendments to other bills, but didn't give details as to exactly when or how.

Sessions said he had not yet talked to White House officials, whom he fought last year on immigration issues, about support for the measures. "The administration can do better," he said.

He also has not spoken about it to Republican presidential candidate John McCain, whom conservatives criticized for co-sponsoring a comprehensive immigration bill that included a path to citizenship for illegal immigrants already in the country. But Sessions said he did not intend anything in the bills to embarrass McCain.

Democratic leaders, who control the Senate schedule, said the measures fall short of what's needed for immigration reform and want to act both on enforcement and on a guest-worker program.

Barrasso's bill would require states to verify that each driver's license applicant is in the United States legally. States that did not do so would lose 10 percent of their federal highway money. Those funds would be redistributed to states that follow the law.

"A driver's license is something one gets as a privilege. It is not a right," he said. "When someone breaks into the country, comes into the United States illegally, that person should never be rewarded with a driver's license."

Wyoming already complies with everything the measure calls for, Barrasso said. Workers at the Wyoming Department of Transportation train to recognize false documents and confiscate them, he added. "To me it's common sense," he said.

Barrasso said the 9/11 hijackers had acquired more than 30 driver's licenses from five states.

Barrasso and Sen. Mike Enzi, R-Wyo., on Wednesday also joined with nine other Republicans to form a "Border Security and Enforcement First" caucus to push such measures.

Sessions wrote three of the bills. One would establish mandatory minimum prison sentences for individuals convicted of entering the United States illegally. Another would require a better workplace enforcement system.