If an incumbency is vacant, the bishop (or the Archdeacon acting on his or her behalf) will usually appoint the churchwardens as sequestrators of the parish until the bishop appoints a new incumbent. The sequestrators ensure that a minimum number of church services continue to be held in the parish, and in particular that the Eucharist continues to be celebrated every Sunday and on every Principal Feast. This duty is usually discharged by organising a regular rota of a few volunteer clergy from amongst either Non-Stipendiary Ministers from within that diocese or in some cases retired clergy living in or near the parish. The bishop will tend to consult the churchwardens before appointing a new priest to take over the parish; in England there is a set process to follow which also involves representatives of the congregation.