Humanists in America are attempting to ban the practice of getting school children to fill shoeboxes with gifts to send to children in deprived parts of the world.
The American Humanist Association wants to stop Operation Christmas Child, run by Franklin Graham's organisaton Samaritan's Purse, from promoting the shoebox scheme.
The goals of the scheme include evangelism and discipleship.
The court case came in the official collection week for the shoeboxes, packed by children throughout the world with pens, colouring pencils, paper, small toys and other gifts for sending to countries in Africa and elsewhere.
The American Humanist Association filed the original lawsuit in 2014 and then appealed in February this Year.
The association's Humanist Legal Center is arguing against the scheme on the grounds of the First Amendment, which ensures freedom of religion and the separation of church and state.
David Niose, legal director of the association, claimed Colarado's Douglas County School District had repeatedly promoted evangelical Christian programs. He specifically mentioned Operation Christmas Child as well as the Fellowship of Christian Athletes programs.
`He said: "As taxpaying citizens with children in the school district, these families object to their schools supporting the efforts of Christian missions to convert children in developing countries. Pressuring students to participate in religious programs in their public schools flies in the face of the separation of church and state that the Establishment Clause demands."
In the UK, the National Secular Society has also criticised the scheme, and claims that it uses poverty and humanitarian aid to evangelise.
Stephen Evans of the National Secular Society told Christian Today that his organisation had been trying to raise awareness of the scheme but that no similar legal action was planned here. "In the US they have the First Amendment 'wall of separation' which we don't have."
A Samaritan's Purse spokesman told Christian Today: "Operation Christmas Child welcomes anyone to participate in this annual Christmas project for children in need around the world. We do not make determinations on individuals or groups that do or do not choose to participate each year.
"Since the project began in 1993, we have been privileged to have tens of thousands of local churches and different organizations participate in Operation Christmas Child—ultimately helping us collect 135 million shoebox gifts so far."
