It is prohibited for anyone other than the priest to be at the altar during the liturgy of the Eucharist. The Holy See says the following:
“In liturgical celebrations each one, minister or layperson, who has an office to perform, should do all of, but only, those parts which pertain to that office by the nature of the rite and the principles of liturgy” *Sacrosanctum Concilium * art.29].
“During the liturgy of the Eucharist, only the presiding celebrant remains at the altar. The assembly of the faithful take their place in the Church outside the “presbyterium,” which is reserved for the celebrant or concelebrants and altar ministers.” Notitiae 17 (1981) 61]
It should be noted that the Church makes no exceptions to this rule, nor are any special dispensations given. “No one, whether lector, extraordinary minister of Holy Communion, deacon, priest, bishop, or even a national conference of bishops, is able to authorize changes in the liturgy that conflict with what has been approved by the Holy See” (*Mass Confusion * pg. 25). Canon 846 says: “The liturgical books approved by the competent authority are to be faithfully observed in the celebration of the sacraments; therefore, no one on personal authority may add, remove, or change anything in them.”
Furthermore, in his Apostolic Exhortation , *Dominicae Cenae * (On The Mystery And Worship Of The Eucharist), Pope John Paul II clearly states that a priest “cannot consider himself a “proprietor” who can make free use of the liturgical text and of the sacred rite as if it were his own property, in such a way as to stamp it with his own arbitrary personal style. At times this latter might seem more effective, and it may better correspond to subjective piety; nevertheless, objectively it is always a betrayal of that union which should find its proper expression in the sacrament of unity.”
