More than half of the Senate Democratic caucus wants the Trump administration to abandon proposals that could curb retirement benefits for federal employees.

“As you continue to develop legislative proposals related to the compensation of federal employees, we urge you to move past draconian cuts that harm the financial security of federal employees in every state across the country, and instead commit to comprehensive reforms that modernize our government’s compensation system in a way that encourages the best and brightest talent to join the ranks of our dedicated civil servants,” the senators, led by Virginia Democrat Mark Warner, wrote in a letter dated Wednesday.

Warner, his Virginia colleague Sen. Tim Kaine and company directed their letter to Jeff T.H. Pon, the director of the Office of Personnel Management.

The senators, who hail from states across the country, suggested that OPM’s proposals to change the Federal Employee Retirement System, known as FERS, could ultimately slash some $143 billion over the next decade.

The senators said that OPM’s explanation for the proposed changes represented a “gross oversimplification of the findings and implications” of a 2017 report from the Congressional Budget Office on federal worker compensation packages.

CBO had found higher compensation for federal employees than comparable workers in the private sector, but Warner and his colleagues pointed out some serious asterisks on that study.

“The report concludes that total compensation costs among workers with a professional degree or doctorate were actually 18 percent lower for federal employees than for similar private-sector employees,“ the senators wrote Wednesday. “To further increase this differential would hamper our ability to hire experts in mission-critical areas.”

“Furthermore, CBO states that the scope of their analysis is limited to selected benefits, and does not include, for example, the stock options that some private-sector firms provide to their employees,” they said.