WASHINGTON (TNND) — With the Nov. 3 midterm elections approaching, millions of ballots are expected to move by mail as the U.S. Postal Service prepares to implement a new rule to track mail ballots and related applications.

Former Federal Election Commission Chairman Trey Trainor told The National News Desk that if the rule does not take effect before Election Day, the major legal fight would likely come afterward. (TNND)

The Postal Service on Thursday published a final rule requiring states to submit voter lists to a federal portal so ballot barcodes can be tracked in and out of the system. The rule also includes the possibility that the Postal Service could refuse delivery for states that do not comply. Whether the rule will be in effect in time for the midterms remains uncertain as legal challenges continue.

This week, the U.S. Supreme Court lifted one injunction affecting the rule and a federal judge lifted another obstacle. Even so, additional lawsuits are being filed, leaving states unsure which procedures will govern mail voting for the midterms.

A coalition of 24 states and the District of Columbia has filed a lawsuit seeking to block the rule ahead of the election. The first military and overseas ballots can be sent out in early September, adding to the time pressure for states and election officials.

Former Federal Election Commission Chairman Trey Trainor told The National News Desk that if the rule does not take effect before Election Day, the major legal fight would likely come afterward.

“If the rules don't take effect in time, then we won't have a legal battle,” Trainor said. “We'll have a legal battle after the election.”

Trainor said that, with the injunctions lifted, the rule is positioned to move forward and states would have to submit their lists. He emphasized that the Postal Service would not be verifying voters, but instead using information already maintained by states.

“It’s important to understand that the Postal Service is not checking on these voters,” Trainor said. “All they are doing is getting a list of the voters that currently exist in the database that the states have.”

Trainor also said the rule is separate from federal efforts related to voter rolls.