Antiphon That they all may be one, as thou, Father, art in me and I in thee; that they also may be one in us; that the world may believe that thou hast sent me.
V I say unto thee that thou art Peter
R And upon this rock I will build my Church.
Collect O Lord Jesus Christ, who saidst to thine apostles Peace I leave with you, my peace I give unto you: regard not our sins but the faith of thy Church; and grant to her peace and unity according to thy will; who livest and reignest with the Father and the Holy Ghost, ever one God, world without end.
This is the form of prayer used through the first sixty years of the twentieth century by Anglo-Papalists, and commended by their organisations. When Ecumenism became broadened (and diluted??), it tended to fall out of use.
After the Chair of Unity Octave mutated into the Week of Prayer for Christian Unity, each day in the Week was assigned to prayer for particular Christian traditions. These intentions differed from time to time.
Personally, I have a soft spot for the old and original Anglo-Papalist title for this Octave: The Chair of Unity Octave. I have adjusted the translation of the Collect to the text of the Ordinariate Missal, which is actually the precise wording of the Devotion as offered for use in the first Walsingham Pilgrims' Manual, suggesting that it be said outside the Slipper Chapel.