Donald Trump urged the US Congress to pass legislation that would allow cabinet secretaries to "remove federal employees who undermine the public trust".
During his State of the Union address, the US President highlighted his efforts to reform the Department of Veterans Affairs (VA).
After Congress passed the Veterans Affairs Accountability Act last year, he said that his "administration has already removed more than 1,500 VA employees who failed to give our veterans the care they deserve, and we are hiring talented people who love our vets as much as we do."
He added: "All Americans deserve accountability and respect, and that's what we are giving to our wonderful heroes, our veterans. Thank you. So tonight, I call on Congress to empower every cabinet secretary with the authority to reward good workers and to remove federal employees who undermine the public trust or fail the American people."
His plans were criticised by Tony Reardon, of the National Treasury Employees Union which represents 150,000 workers.
"It is unfortunate that the President chose to single out our world-class civil service tonight leaving the impression that federal employees are not dedicated to public service, committed to the missions of their agencies and honourable Americans," he told Federal Computer Week magazine.
Walter Shaub, the former director of the Office of Government Ethics under Barack Obama, also criticised the plans.
"POTUS calling on Congress to remove civil service protections for feds serves the goal of politicising the career ranks, and it comes on the heels of Paul Ryan saying he wants to 'cleanse' the FBI," he tweeted after Mr Trump's address.
"There's a reason America did away with the spoils system. (Hint: banana republic)".
Following his inauguration last year ordered a government hiring freeze in a bid to reduce the size and cost of the federal workforce, delivering on a key campaign pledge.
Four months later Mick Mulvaney, director of the Office of Management and Budget (OMB), told agency heads in a memo that they should "maximise employee performance" and consider "removing poor performers".
A review should be undertaken of workers on leave over "deficiencies" or misconduct claims and action, including firing if necessary, should be taken, he added.
