On Tuesday, the Biden administration plans to announce an executive action protecting undocumented spouses of American citizens that would shield about 500,000 immigrants from deportation, according to four sources familiar with the matter.

“This is the biggest thing since DACA,” said one of the sources, an immigration advocate, adding that it was a smart political move by the Biden administration.

The four sources, which include advocates and Capitol Hill staffers, said that lawmakers have been briefed and at least some have been invited to the White House for the announcement.

NBC News reported last week that an executive action protecting the spouses was likely to be announced soon.

The program, known as “parole in place,” would also make it easier for some undocumented immigrants to get a green card and a path to U.S. citizenship.

The sources also say that the undocumented spouses would be allowed to obtain work permits on a case-by-case basis. Two of the sources said that the undocumented spouses will have to have lived in the U.S. and been married for at least 10 years before being eligible to apply for the work permit.

Three of the sources said that President Joe Biden will also announce a new action regarding DACA recipients who earned degrees in higher education and are seeking a job in that same field.

The planned actions come after immigration advocates and Democratic lawmakers urged the administration to prioritize long-term undocumented immigrants and as Biden tries to court Latino voters in crucial battleground states such as Nevada and Arizona.

The moves are expected to be challenged in court.

This article was originally published on NBCNews.com