Opponents are suing to end a federal program that could potentially give nearly half a million immigrants without legal status who are married to U.S. citizens a path to citizenship.

Sixteen Republican-led states filed suit Friday to halt the program launched by President Joe Biden in June, saying in court filings that the Biden administration bypassed Congress to create a pathway to citizenship for “blatant political purposes.”

Under the newly implemented policy, many spouses without legal status can apply for “parole in place,” which offers permission to stay in the U.S., apply for a green card, and eventually obtain a path to citizenship.

However, the program has faced significant opposition, especially in an election year where immigration is a hot-button issue, with critics claiming it is tantamount to granting amnesty to individuals who entered the country unlawfully.

Texas Attorney General Ken Paxton criticized the plan, stating that it “violates the Constitution and actively worsens the illegal immigration disaster that is hurting Texas and our country.”

The lawsuit, filed against the Department of Homeland Security, DHS Secretary Alejandro Mayorkas, and other Biden administration officials, alleges that the agency is abusing its power by attempting to grant parole to spouses in large numbers.

To be eligible for the program, immigrants must have lived continuously in the U.S. for at least 10 years, not pose a security threat, have no disqualifying criminal record, and have been married to a citizen by June 17.

Applicants are required to pay a $580 fee, submit a detailed application with supporting documents, and explain why they deserve humanitarian parole.

If approved, individuals have three years to seek permanent residency and can obtain work authorization during that period. The administration estimates that around 500,000 people could be eligible for the program, along with approximately 50,000 of their children.

Prior to this initiative, obtaining a green card for those in the U.S. illegally after marrying an American citizen was a complex and uncertain process, often requiring individuals to leave the country and risk not being permitted to return.