(CNN) - Thursday is the National Day of Prayer but the annual observance that began in 1952 is now the center of controversy.
Last month, a federal judge declared it unconstitutional because it violates the ban on government-backed religion.
President Obama and the National Day of Prayer Task Force, a privately funded group, are fighting the decision.
President Obama issued a National Day of Prayer proclamation but will not hold an interfaith observance at the White House.
There will be National Day of Prayer events held across Washington including services at the Pentagon and the steps of the Capitol.