Updated

Abortion rights activists were lobbying lawmakers Wednesday in an effort to torpedo tougher restrictions on abortion coverage in the health care legislation that is being debated in the Senate.

The protest came as a bipartisan group of anti-abortion senators, including Sens. Ben Nelson, D-Neb., and Orrin Hatch, R-Utah, prepared to offer an amendment similar to one authored by Michigan Rep. Bart Stupak that passed on the House side and prohibits insurance companies from offering abortion coverage in subsided plans even if women use their own money to purchase those plans.

Wednesday's rally is being held by the Coalition to Pass Health Care Reform and Stop Stupak!, which describes itself as "a broad group of advocacy organizations including progressive groups, women's health groups, organizations representing youth, communities of color, and people of faith and health professionals."

A release from the group said "hundreds" of people would lobby their representatives with a message that the Stupak language "will take existing benefits away from women and jeopardize women's health."

Among the activists protesting are Alliance for Justice, MoveOn.org, Planned Parenthood, and the YWCA.

Another group, FDL Action PAC, is phone banking into the districts of Democratic lawmakers who voted for the Stupak amendment. The calls, which are targeting pro-choice likely voters in the next year's mid-term elections, are asking them to demand that their lawmakers not cast a final vote on the Stupak amendment.

The protest illustrates the deep split that the abortion issue has created on and off Capitol Hill in the health care debate.

"By confusing abortion with health care, the feminist groups and the abortion lobby actually demean women with their argument that the destruction of unborn children is essential to feminine power," said Charmaine Yoest, president and chief executive of Americans United for Life.

Senate Majority Leader Harry Reid has faced criticism from a number of groups and lawmakers for writing a bill that did not include similar restrictions to the Stupak amendment. Nelson earlier questioned the Senate plan to build a firewall between federal and private funds. He called the leader's move "complex" and asked to be briefed on how it would work.

The appearance of the amendment suggests Nelson and some of his colleagues are not convinced the current language will adequately restrict taxpayer funds from going toward abortion. Hatch, though, acknowledged it may be tough to get the 60 votes needed to pass the amendment.

"We're not talking about doing away with abortion. We're talking about refusing to have federal funds pay for it," he said.

Anti-abortion groups earlier applauded Nelson for announcing he would filibuster any final bill if the abortion language is not changed. Reid needs 60 votes to get health care legislation off the Senate floor and move it closer to the president's desk, so losing even one of his 60 Democrats could be a fatal blow to the overhaul.