As millions of voters prepare to vote by mail, the Postal Service gave back five weeks of gains that restored first-class mail delivery service close to levels that predated changes brought on by Postmaster General Louis DeJoy. By the beginning of October, the agency delivered 86 percent of first-class mail on time, down from 90.6 percent before the changes took effect in July, and down from nearly 89 percent at the start of September, according to Postal Service and Postal Regulatory Commission data analyzed by the office of Sen. Gary Peters (Mich.), the chamber’s top Democrat in charge of postal oversight.

The assessment comes as the Postal Service attempts to resolve five overlapping federal court orders that blocked implementation of DeJoy’s cost-cutting agenda. The agency is pushing to restore voters’ and election officials’ confidence in the mail system even as tens of millions of Americans have already received — and millions have cast — their ballots. The Postal Service is preparing to deploy extra personnel and transportation and processing resources in expectation of an influx of ballots. It held a background briefing with journalists earlier in the week to describe its plans for election mail.

Officials said the agency had already delivered a record 417 million pieces of election mail — including ballot applications, voter information and 64 million ballots. That compares with 200 million during the entire 2016 election cycle.