The US Conference of Catholic Bishops is calling on worshippers to fast and pray during the period leading up to the Supreme Court’s decision on two equal marriage cases.

The Bishops Conference made the request in a bulletin, which was issued by Cardinal Timothy Dolan.

Catholics have also been asked to make personal sacrifices to help the court make a ruling that supports its official opposition to marriage equality.

“Be a witness for the truth of marriage in word and action. Take advantage of opportunities to speak about marriage’s unique meaning in conversation with friends, family, neighbours or co-workers,” the bulletin stated, adding: “A broad negative ruling could redefine marriage in the law throughout the entire country, becoming the ‘Roe v. Wade’ of marriage.”

The Supreme Court is expected to soon issue rulings on the federal Defence of Marriage Act (DOMA), and on California’s Proposition 8 same-sex marriage ban.

The decisions on these two cases are expected by late June.

In March, a poll showed 54% of US Catholics support equal marriage – a rise of 5% since last December.