A federal whistleblower has warned that the US Postal Service's new online portal for screening mail-in ballots is untested and could suffer "catastrophic failure" if brought into use before November's midterm elections. The system is being rushed into service as President Donald Trump pushes for greater federal oversight of postal voting, a move currently tied up in the courts after a Boston judge temporarily blocked his executive order, with the case now heading to appeal and likely the Supreme Court.

The whistleblower report, passed to Senator Richard Blumenthal by the advocacy group Whistleblower Aid, describes the portal's development as "rushed", "risky" and "haphazard", blaming an "impossible" timeframe set by Trump for verifying ballots against state voter lists. Compounding the risk is a newly adopted "zero-percent failure" standard, which the report says could see tens of thousands of ballots rejected over minor issues, such as a barcode error or an unupdated address, with no clear route of appeal. States including North Carolina and Alabama are due to begin mailing ballots within days, and Blumenthal noted that a third of Americans vote by post.