A group of Internal Revenue Service workers in Philadelphia were among those laid off Thursday within the federal agency, which already struggles to answer taxpayer calls in a timely manner, according to a union representative.

At least 400 IRS employees in Philadelphia are among the thousands expected to be laid off by the end of this week.

The IRS purge was the latest and most extensive batch of firings of federal employees in Philadelphia, part of a nationwide downsizing of the government workforce by the Trump administration that has reportedly hit more than 10,000 workers.