By MATTHEW JAFFE

More than 100 members of Congress wrote President Bush today, urging him to "halt all action" on a proposal they argue would change the definition of abortion, and drastically limit women's access to birth control.

The Department of Health and Human Services draft proposal, which began circulating around Capitol Hill last week, would require hospitals receiving federal funds to certify that, in their hiring, they do not discriminate against people who refuse to provide forms of contraception, such as birth control pills, due to personal religious beliefs.

The proposal immediately incited an uproar among Democratic lawmakers led by Sen. Hillary Clinton, D-N.Y., and Sen. Patty Murray, D-Wash., who have also written to Bush. Now, 104 members of the House of Representatives have sent the president a protest letter of their own.

"The draft regulation could have a disastrous effect upon access to safe and effective birth control for millions of women across the country," the protest letter warns.

"The regulation's definitions are so broad as to go far beyond abortion politics and threaten virtually any law or policy designed to protect women's access to safe and effective birth control. The department does this primarily by defining 'abortion' in a way that could sweep in many common forms of birth control," the lawmakers write in the letter.

"It would allow any provider, who wants to deny a woman emergency contraception or even birth control pills, to claim protection based on a personal belief that such pills fit the regulatory definition."

Current federal law prohibits health care providers and organizations from discriminating against people who won't provide abortions or birth control. The Bush administration's new draft proposal would require these agencies to certify in writing their compliance with the law before getting funding from HHS. The department issued a statement last week saying the draft proposal was simply an attempt to enforce anti-discrimination laws.

"Over the past three decades, Congress has passed several anti-discrimination laws to protect institutional and individual health care providers participating in federal programs. HHS has an obligation to enforce these laws, and is exploring a number of options," HHS said in the statement.

However, congressional critics, expressing their "profound disagreement," wrote today that the draft proposal would go far beyond just enforcing these laws.

"The federal statutes at issue here were, in general, designed to shield different types of health care providers who did not wish to provide abortions. The draft regulation being circulated at HHS would go much further," the House lawmakers' letter said. "By distorting the scope of the laws, it would gut state and local protections of women's right to safe and effective birth control. This is not a technical clarification regarding abortion services. This is a radical reversal of decades of public health work to provide contraception and family planning services that have enjoyed wide bipartisan support."