The federal “self-deportation” pilot program ending Friday has drawn only a handful of illegal immigrants volunteering to return to their home countries, but immigrant-rights advocates who ridiculed the effort now wonder if it will used to justify or even escalate workplace raids.

U.S. Immigration and Customs Enforcement offered the three-week pilot program in five U.S. cities, giving illegal immigrants facing court orders to leave 90 days to plan their departure and coordinate travel with relatives instead of facing the prospect of being arrested, detained and deported. The program was well publicized but only six people signed up in the first week.

Immigrant advocates said the program had few incentives and failed to consider undocumented immigrants’ ties to family in the U.S. They said they worry that ICE will cite the weak turnout as a reason to step up the raids, since it now can say that it made an effort to enforce the law in a way that was less disruptive to illegal immigrants and their families.

“My hope is it isn’t going to empower them or fuel their enforcement even further,” immigration lawyer Lisa Ramirez said Thursday.

ICE said it hatched the plan to quell criticism of the surge in workplace raids. One supporter of the agency said the low turnout will help insulate federal immigration agents from some of the criticism.

“It was calling their bluff,” said Ira Mehlman, a spokesman for the Federation for American Immigration Reform.

ICE offered the program to 457,000 illegal immigrants nationwide who have ignored judicial orders to leave the country but have no criminal record. Applicants could sign up at ICE offices in Charlotte, N.C., Chicago, Phoenix, San Diego and Santa Ana.

The program was criticized for offering little incentive for illegal immigrants to step forward since they would be barred from returning to the United States for as long as a decade.

And while ICE has increased arrests of illegal immigrants who fail to heed court orders to depart, several immigrants said many people feel they have a decent chance of sticking it out here longer than the government would give them if they came forward.

“Why are they going to go back to their country and pay someone to bring them over here again?” asked Rigoberto Moreno, 46, who entered the country illegally from Mexico as a teenager in the 1970s and has since become a U.S. citizen.