WASHINGTON (RNS) A coalition of mostly conservative religious organizations is urging Congress to amend a proposed bill that would bar them from making personnel decisions based on religion if they receive government funds to treat mental illness and substance abuse.

In a letter sent Wednesday (Aug. 25) to every member of Congress, evangelical charities, the U.S. Catholic Bishops, and Orthodox Jews say the bill “would be catastrophic” to their religious freedom and to their mission to serve the needy.

The bill, HR 5466, would reauthorize federal funding to treat substance abuse and mental illness, and was introduced in May by Rep. Patrick Kennedy, D-R.I., who has battled addiction and bipolar disorder.

The bill would outlaw any government funds or contracts with religious organizations that do not agree to “refrain from considering religion or any profession of faith” when making employment decisions.

“Stripping away the religious hiring rights of religious service providers violates the principle of religious freedom, and represents bad practice in the delivery of social services,” said Anthony Picarello Jr., general counsel of U.S. Conference of Catholic Bishops.

World Vision, the Christian humanitarian giant, also protested the proposed bill. On Monday (Aug. 24), a federal appeals court ruled that World Vision can fire employees who do not share its theological tenets.

But government funding for religious charities that make personnel decisions based on religion is far trickier. The Obama administration has said it is weighing the issue and will make decisions on case-by-case basis until a final decision is rendered.

The religious groups protesting the proposed bill also wrote an open letter to Attorney General Eric Holder, urging him not to “dilute the right of faith-based” charities to “stay faith-based through their hiring.”

They also vowed that no government funds will be used for proselytizing or any other religious activities, and that all people in need will be served, regardless of faith.

A church-state watchdog group noted the relatively thin sliver of religious groups that signed the letter. Most Jewish and mainline Protestant groups — not to mention Buddhists, Quakers, Hindus, Muslims and Mormons — did not sign the letter. Instead, many of the 100 signatories are presidents of small Christian colleges.