Delegates to the annual convention of the Episcopal Diocese of Washington last weekend vigorously debated proposed revisions to the Book of Common Prayer.

An updated version of the prayer book's centuries-old services will be considered for final approval at the church's general convention in September.

At the Washington meeting, the vestry of Christ Church in Georgetown proposed that if the prayer book revision is approved, the church also authorize the "continued use of services and prayers from the 1928 Book of Common Prayer as alternative authorized liturgy."

Jewel Davis of Christ Church said that approval of both prayer books "may provide a means of easing the disenchantment abroad in the church."

The Rev. Edgar D. Romig of Epiphany Church argued, however, that authorization of both books would promote division within the church. Romig noted that the Episcopal Church constitution authorizes "one Book of Common Prayer and one book only."

Bishop John T. Walker of the Diocese of Washington told the convention "there will be a proposal to the general convention clearly indicating that after Jan. 1, 1980, there would be one prayer book."

Walker assured the delegates, however, that the issue will be dealt with "in a pastoral way," and added, "I have said repeatedly that there will be no fiat coming from my office demanding that you get rid of the 1928 prayer book on Jan. 1."

James R. Slay, a lay delegate who supports the 1928 prayer book, said "there are those among us who have been deeply hurt" by the church's prayer book revision.

"Some have voted with their feet," Slay said, referring to members who have left the church. "I am not saying that if you don't do this we will leave but I ask you to do it in a sense of healing," Slay told the convention.

Others argued that significant portions of the 1928 prayer book are included, for optional usage, in the revised version. The updated version was tentatively approved at the 1976 general convention in Minneapolis. If the revised prayer book receives that approval in September, it will become the official prayer book of the church.

Prayer book changes, as well as ordination of women to the priesthood, caused some parishes elsewhere in the country to split from the Episcopal Church.

Walker, in his annual report to the diocese, told the convention that parish response to requests for financial contributions has been "unbelievably high."

Walker said the parishes have pledged "just over 100 percent" of the funds asked to support the diocesan budget.

Parish contributions make up about 75 percent of the diocesan budget, which totals $1.04 million for 1979.

Walker also announced plans to hire an assistant bishop for a set term of employment during which time the assistant will be delegated specific duties.

Traditionally, large dioceses such as Washington elect a suffragan bishop to assist the diocesan bishop. The suffragan bishop, once elected, "is ensconced in a place until he may be elected to another position in the church, resigns, retires or dies," Walker told the convention. That system of unlimited term of service has caused continuing problems in the church, he said. Walker was suffragan bishop here before he was elected diocesan bishop.

During the convention, the Rev. Charles Perry, provost of the Washington Cathedral, described the operating budget for the financially troubled institution as "in balance." The cathedral's debt, incurred largely for past construction, "has been reduced to $8 million, but the interest burden is crushing," Perry said.

The delegates to the convention also defeated a resolution that criticized the World Council of Churches for its $85,000 grant last summer to the Patriotic Front in Rhodesia, an alliance of black nationalist forces opposed to the biracial government there.