In an 8-page pamphlet released this week, the Irish Catholic Bishops' Conference called on Irish voters to reject a referendum on whether to allow gay couples to marry.

Ireland's government announced last month the decision to hold the national vote sometime in mid-2015 as part of a special “constitution day.”

In the pamphlet, titled The Meaning of Marriage, the bishops argue that legalizing such unions in Ireland would be “a grave injustice” and hurt society.

“It is a grave injustice if the State ignores the uniqueness of the role of husbands and wives, and the importance of mothers and fathers in our society,” the pamphlet states.

“The union of marriage provides for the continuation of the human race and the development of human society. Marriage of a woman and a man is a fundamental building block of society which makes a unique and irreplaceable contribution to the common good and to society as well.”

Legalizing such unions “would deprive children of the right to a mother and father,” the bishops wrote.

In launching the pamphlet, Bishop Liam MacDaid, chair of the conference's council for marriage, said that allowing gay couples to marry would “be a disservice to society rather than a service.”

A government poll released last year found overwhelming support (73%) for marriage equality.

(Related: Colin Farrell makes personal appeal to Irish people on gay marriage proposal.)