President Donald Trump asked the Supreme Court on Tuesday to reinstate a controversial citizenship records system his administration has sought to wield for sweeping reviews of state voter rolls.

Voter roll audits using the Department of Homeland Security data program known as SAVE (Systematic Alien Verification for Entitlements) have been on hold in most of the country since a lower court found that the administration violated privacy law in how it beefed up the program for voter purges.

Critics of the program argue that it produces inaccurate results wrongly identifying eligible voters as non-citizens and could lead to flawed purges that disenfranchise voters.

Trump has made the program a central tool in his government-wide effort to find proof of non-citizen voting. For at least a decade, Trump has claimed that foreigners are tainting elections – allegations that have been debunked in numerous studies of non-citizen voting that have found it to be a rare occurrence.

US Solicitor General John Sauer argued in the new filing that the “indefensible” ruling by the lower court “threatens the integrity of upcoming elections.”