Under the landmark policy, which took effect today, those under 30 who meet certain criteria will be spared deportation for two years, subject to renewal, and will be eligible to apply to work legally.

This offers amnesty to the many, largely Hispanic, immigrants who came to the US as children but have for years faced the prospect of expulsion, despite being law-abiding citizens who have worked or studied in the country.

NAFSA said it was a step forward for immigrant students. “It will offer urgently needed reprieve, on a rigorous case-by-case basis, for [students] who currently find themselves, through no fault of their own, in an untenable and frightening legal limbo,” the body said in a statement.

“Undocumented students, brought to the United States by their parents as children, today live under the constant threat of deportation and are unable to contribute productively to the only country they call home.”

“Undocumented students live under the constant threat of deportation”

There are an estimated 800,000 undocumented immigrants under 30 in the US. Criteria for their staying relate to age, length of residency in the US and criminal history. They must also be in, or have graduated from, education or have served in the military.

The move has been described by some as a “partial” DREAM act – a policy that has failed to pass the senate since 2001 which would grant permanent residency to undocumented immigrants, subject to conditions. Aside from the humanitarian arguments for the act, supporters say it could add up to $3.6 trillion in taxable income to the economy and boost the number of college graduates in the US.

NAFSA, which along with the President backs a full DREAM act, said: “The administration’s action [today] moves to do what is right and humane in the case of these individuals, giving Congress the room to do its long-delayed and still-urgent job: to pass the DREAM Act and confer the benefits in that act by law.”