The Baltimore Sun:

With legislation to legalize same-sex marriage expected in the General Assembly, Maryland's Roman Catholic bishops are calling on parishioners to act against the proposal and other measures that they say threaten "religious liberty."

In a 16-page statement sent to parishes throughout the state, the bishops say a same-sex marriage law would lead to violations of First Amendment rights.

"Religious liberty and the right of conscience will be further eroded unless the Catholic community stays informed about the challenges these rights face and the reasons why they are integral to a just society," said the statement, entitled "The Most Sacred of All Property: Religious Freedom and the People of Maryland."

The statement is signed by Edwin F. O'Brien, the former archbishop of Baltimore who has been given a new assignment in Rome; Cardinal Donald Wuerl, archbishop of Washington; and W. Francis Malooly, bishop of Wilmington, Del.

Kathy Dempsey, a spokeswoman for the Maryland Catholic Conference, said the statement — crafted with support from national Catholic leaders — has been in the works for a year. It is being distributed in Maryland now, she said, partly in anticipation of the annual General Assembly session that begins in January.

Gov. Martin O'Malley has pledged to lead the charge for a law to recognize same-sex marriage in the state, saying he would include the effort among his priorities during the 2012 session.