VATICAN (CWNews.com) -- Virtually every major Christian denomination will be represented at a Vatican ecumenical service on January 18, when Pope John Paul II will open the Holy Door at the basilica of St. Paul Outside the Wall, at the beginning of the annual week of prayer for Christian unity.

    The ceremony will take place in the atrium of the basilica, which is built on the site where-- according to tradition-- the Apostle Paul was buried in the year 67. The service will include readings from Scripture and the singing of hymns, after which the participants will join the Holy Father for lunch at a neighboring Benedictine abbey.

    The Pontifical Council for Christian Unity has not yet released a full list of participants, pending some late responses to the invitation. However, Vatican sources indicate that 35 church bodies have already confirmed their intent to participate-- in many cases, sending two or more representatives. Many of the participants will be housed at the St. Martha House inside the walls of the Vatican.

    The patriarchs of the Orthodox churches have, for the most part, named prominent metropolitans to represent them at the service. The Archbishop of Canterbury, George Carey, will himself attend.