President Donald Trump took his contentious bid to end birthright citizenship in the United States to the Supreme Court on Thursday.

Trump’s executive order seeking to end birthright citizenship, which he signed on his first day in office, was blocked by federal district courts in Maryland, Massachusetts and Washington state.

Birthright citizenship is enshrined in the 14th Amendment to the US Constitution, which decrees that anyone born on American soil is a citizen, and Trump’s order seeks to end it for children whose parents are in the country illegally.

In an emergency application with the Supreme Court, the Justice Department sought to narrow the scope of the nationwide lower court injunctions to the individual plaintiffs in the three cases.

The department’s acting solicitor general Sarah Harris described it as a “modest” request and she notably did not seek a ruling from the Supreme Court at this time as to whether eliminating birthright citizenship is constitutional or not.

“Those universal injunctions prohibit a Day 1 Executive Order from being enforced anywhere in the country,” Harris wrote.

“While the parties litigate weighty merits questions, the Court should ‘restrict the scope’ of multiple preliminary injunctions that ‘purport to cover every person in the country,’ limiting those injunctions to parties actually within the courts’ power,” she said.

Trump has been facing legal pushback in courts across the country as he attempts to stem illegal immigration, slash the government budget and reduce the federal workforce.

In his latest setback, a district judge in California on Thursday ordered six federal agencies to rehire thousands of probationary workers who had been fired.