An anti-immigration group is calling on the Obama administration to ensure a smooth exit for illegal immigrants who are trying to leave the U.S. due to the weak economy and Arizona's strict new immigration law.

Americans for Legal Immigration PAC (ALIPAC) is urging U.S. citizens to pressure the White House and the Homeland Security Department to establish "safe departure" border checkpoints along the U.S. border for illegal immigrants so they can leave without fear of being detained or prosecuted for immigration crimes.

"The peaceful and gradual exodus of illegals from Arizona shows there is no need for comprehensive immigration reform amnesty," William Gheen, president of the group, said in a written statement. "Comprehensive immigration enforcement works and has the desired effect without mass deportations."

Gheen said the safe passage would ensure that illegals "leave in an orderly fashion, instead of trying risky desert crossings, paying money to the cartels for passage south, or fleeing to other states."

"This is about the only situation we would ever advocate that our immigration laws be waived," Gheen said. "We want to encourage the illegals to leave America on their own and thus we ask Obama to provide them safe passage out of America."

Neither the White House nor Homeland Security responded to e-mails seeking comment.

The call comes as the Obama administration seeks an injunction in federal court to block Arizona's immigration law, set to take effect on Thursday, that would make illegal immigration a state crime and require police to check the residency status of anyone they suspect of being an illegal immigrant. A ruling on the case is expected Tuesday night or Wednesday morning.

An estimated 100,000 illegal immigrants have left Arizona in the past two years as it cracked down on illegal immigration and its economy was hard hit by the recession. A Department of Homeland Security report on illegal immigrants estimates Arizona's illegal immigrant population peaked in 2008 at 560,000, and a year later dipped to 460,000.

It is not clear how many have left since the new law passed in April. Some are leaving the U.S. and others are heading to neighboring states.

A pro-immigrant group called the safe passage proposal "a little suspicious."

"I think it's clearly part of the attrition strategy. Make things so horrible for immigrants that they will self deport," said Sarahi Uribe, a regional organizer for the National Day Laborer Organizing Network. "But while it's true some people are leaving Arizona, a great deal of people are staying."

Uribe dismissed Gheen's idea as a "thinly disguised" strategy to "drive people out of the state of Arizona."

"It's kind of sick they would paint this as humanitarian relief when Arizona's immigration law has created a humanitarian crisis."

Gheen told FoxNews.com that he would not want safe passage for illegal immigrants accused of serious criminal offenses, such as murder or rape.

"The main thing is, we just want them to leave," Gheen said, adding that if all immigration laws were enforced, the number of illegals would be reduced to less than 1 million in 10 years.