The top US Republican in Congress has called for action against a White House contraception rule that has angered Catholic leaders.
Speaker John Boehner said legislation was needed against the rule, which means Church-linked institutions must buy health insurance that covers birth control costs.
Catholic leaders say that would force them to violate religious beliefs.
White House officials say they want to find ways to allay Church concerns.
But one report in the New York Times on Wednesday said the administration would not back down from the rule.
Under President Barack Obama's healthcare reform law, employers must offer insurance that includes contraceptives.
Churches and other houses of worship were given a waiver under the new law, but institutions including Catholic universities and hospitals are not exempt.
'Must not stand'
Mr Boehner, a Republican from Ohio, took to the floor of the House of Representatives on Wednesday to call for legislation against the rule.
"This attack by the federal government on religious freedom must not stand and will not stand," he said.
The speaker said the House Energy and Commerce Committee was working on legislation related to the rule.
The mandate has also provoked strong condemnation from the Republican presidential candidates on the campaign trail.
In Colorado on Tuesday, Mitt Romney described the policy as a "violation of conscience".
But the White House and other Republican candidates have hit back at his criticism.
During Mr Romney's tenure as governor of Massachusetts, the state passed legislation that required hospitals - including Catholic ones - to provide emergency contraception to rape victims.
He vetoed the law, but this was over-ridden by state lawmakers.
Democratic congresswomen have defended the White House measure, arguing that the policy would control health costs, stop unwanted pregnancies and that overturning the rule would adversely affect staff who may not be Catholic.
Jan Schakowsky, a Democratic Representative from Illinois, said: "Women's healthcare should not depend on who the boss is."
Wisconsin Representative Gwen Moore said the church "can't impose its religious views on people and whether they can have healthcare".
The uproar began over the weekend, after US Health Secretary Kathleen Sebelius defended the policy in an editorial for USA Today.
Catholic bishops called for the rule to be dropped, including Archbishop Timothy Dolan of New York, who wrote in an editorial for the Wall Street Journal that the mandate was "an unprecedented incursion into freedom of conscience".
The Obama administration has sought to portray the issue as a balance between religious freedoms and preventing discrimination under the new healthcare law.
"You are going to have folks of all faiths who work for those large institutions," White House spokesman Jay Carney said in a Tuesday press briefing.
"Those women ought to be able to have access to the same contraceptive services that other women will have access to."