Barack Obama has been accused of backtracking on an assurance that he made in a 2009 speech at the University of Notre Dame

Roman Catholic leaders have furiously criticised President Barack Obama for approving new regulations that compel religious organisations to include morning-after pills and other contraceptives in employee health insurance coverage.

Roman Catholic leaders have furiously criticised President Barack Obama for approving new regulations that compel religious organisations to include morning-after pills and other contraceptives in employee health insurance coverage.

New rules, introduced under Mr Obama's overhaul of the US healthcare system, mean that religious charities, universities and other groups must now provide contraception in staff insurance packages.

Failure to do so would result in fines being levied by the federal government that larger Catholic organisations claim would cost them millions of dollars a year.

At least 153 US bishops have spoken out against the change. A letter from a leading bishop, accusing the president of waging a "severe assault on religious liberty", has been read to dozens of congregations.

"We Catholics will be compelled to either violate our consciences, or to drop health coverage for our employees and suffer the penalties for doing so," wrote Alexander Sample, the Bishop of Marquette.

Mr Obama has been accused of backtracking on an assurance that he made in a 2009 speech at the University of Notre Dame, a leading Catholic university in Indiana.

Speaking specifically about his planned health reforms, he said: "Let's honour the conscience of those who disagree with abortion, and draft a sensible conscience clause".

A White House spokesman said the reforms, which do not apply to the Church itself, struck "an effective balance between religious beliefs and increased access to important preventative services".

The row threatens to damage Mr Obama's support in November's presidential election among Catholic voters, a group he won by 54 per cent to 45 per cent over his Republican rival John McCain in 2008.

Timothy Dolan, the Cardinal-designate of New York and president of the US Conference of Catholic Bishops, urged Catholics across America to bring political pressure to bear.

"Let your elected leaders know that you want religious liberty and rights of conscience restored and that you want the administration's contraceptive mandate rescinded," he said.