Rudy Giuliani on Wednesday called on Congress to prohibit states from giving driver's licenses or similar forms of identification to illegal immigrants, the latest development in an issue that burst onto the campaign scene during a Democratic presidential candidates debate last week.

After accepting an endorsement in Washington, D.C., from Christian conservative Pat Robertson, Giuliani said he called Republican Reps. Pete Sessions of Texas and Peter King of New York that morning to propose the legislation. He said while he doesn't know if a bill will be written, he urged a bill that would close a loophole allowing states to grant the licenses to illegal immigrants.

"There seems to be ... a loophole that allows states not (to) give a license that would be a real ID but some other form of a license. That would make things hopelessly confusing for the immigration service," Giuliani said.

The Republican frontrunner added that Democratic candidate Hillary Clinton's proposal to allow states to decide whether to grant the licenses could obstruct the ability of the federal government to secure the borders.

King told FOXNews.com that he and Sessions are working on a bill to introduce next week. He said the issue has been building over the last several weeks, but the way it was handled at the Democratic debate presented an opportunity to address the issue in Congress.

"In politics and government, you always try to pick the right moment to strike. ... Wth the issue being so much on the radar screen, it'll be much easier to get co-sponsors on the bill," King said.

After giving a confusing position during a debate last week, Clinton's campaign has clarified that she supports a New York state plan to give illegal immigrants driver's licenses. But in an interview with a cable news channel Tuesday, she said the need for the program will be for each state to decide.

In response, Giuliani said he never thought of Clinton as a federalist — someone who values states' rights acting independently of a central government — but that federalism is not the answer on this issue.

"The idea is the federal government is supposed to secure the borders, the federal government is supposed to regulate immigration. If we had 50 different regulations for immigration in the United States, it would become the picture that we have right now, which is a very, very confusing picture."

FOX News' Mosheh Oinounou and Judson Berger contributed to this report.