These are the agencies Trump is purging during the shutdown

President Trump and his administration are prepared to lay off thousands of federal workers on Friday, using the government shutdown as an opportunity to target agencies that aren't aligned with the president's views.Why it matters: The mass layoffs could further decimate a federal workforce already down 200,000 employees since Trump retook office, sending away thousands more who are in charge of crafting America's health care, education and environmental policy. What they're saying: A spokesperson for the largest federal employee union, the American Federation of Government Employees, told Axios that the Trump administration is "illegally" firing thousands of workers who provide "critical services" to communities across the country."In AFGE's 93 years of existence under several presidential administrations — including during Trump's first term — no president has ever decided to fire thousands of furloughed workers during a government shutdown," they said.The federation is also suing the administration on behalf of its over 800,000 members.The White House declined to comment on the layoffs, referring Axios to the Office of Management and Budget, which said the layoffs are underway and "substantial."Here's what we know about the currently affected agencies, and what public services they offer:Health and Human Services DepartmentHHS would not immediately confirm how many employees will receive layoff notices or which departments will be affected."HHS employees across multiple divisions have received reduction-in-force notices as a direct consequence of the Democrat-led government shutdown," a spokesperson told Axios' Maya Goldman and Tina Reed.The layoffs come after a wave of scientists already voluntarily or involuntarily left the department earlier this year due to concerns about Secretary Robert F. Kennedy's leadership.The department is tasked with overseeing Medicare and Medicaid, which together provide health care for nearly 40 percent of Americans, including children. The department also administers the Temporary Assistance for Needy Families (TANF) and Head Start programs. The HHS also includes the Centers for Disease Control and Prevention, which monitors for emerging health threats.The Department of Homeland SecurityA DHS spokesperson told Axios that reductions in force "will be occurring" at the Cybersecurity and Infrastructure Security Agency, which aims to reduce threats to America's cyber and physical infrastructure."This is part of getting CISA back on mission," they said in an emailed statement.DHS did not answer Axios' questions on if the layoffs would affect Immigrations and Customs Enforcement, the agency in charge of carrying out the president's massive detainee and deportation programs.It also did not confirm if there would be any cuts to the Federal Emergency Management Agency (FEMA) which prepares for natural disasters and responds to emergencies.The Treasury DepartmentA Treasury spokesperson confirmed to Axios that employees at the nation's primary financial agency were notified that they were being let go on Friday.According to a lawsuit filed by the AFGE, approximately 1,300 notices were sent out.The Treasury Department presides over a variety of agencies in charge of fiscal policy, including; the Internal Revenue Service, which collects taxes; the U.S. Mint, which issues coins as well as commemorative medals; and the Financial Crimes Enforcement Network.The Education DepartmentEducation employees will be "impacted by the RIF," a spokesperson confirmed to Axios on Friday.The department would not detail which department offices would be affected.By the numbers: Roughly 50% of the department's workforce was let go in March, turning the department tasked with administering financial aid and funding, equal access for marginalized student populations and providing oversight for education policy into a skeleton crew.The cuts come after the Supreme Court in July allowed Trump to move forward with his plan to dismantle the department.The Environmental Protection AgencyA union representing EPA employees told Axios that agency employees were informed of impending layoffs Friday. "Using our jobs as political leverage is an unprecedented and illegal abuse of power," Justin Chen, President of AFGE Council 238 said in an emailed statement.The EPA is charged with protecting air quality, preventing water pollution, and overseeing hazardous waste disposal.The Department of Housing and Urban DevelopmentA spokesperson for HUD confirmed to Axios that the department has also sent out layoff notices: "HUD is implementing a reduction in force to align our programs with the Administration's priorities and the appropriations available to the department."The department provides housing assistance and operates several programs tasked with ensuring equal access to homeownership for veterans, impoverished families and historically marginalized communities.The Energy DepartmentThe agency tasked with the nation's energy research, conservation, and nuclear weapons is also being hit with layoff notices, a source familiar with internal policy confirmed to Axios.Go deeper: Trump officials say "substantial" federal worker layoffs have begunEditor's note: This story has been updated with a HUD statement.