Plans for the union of St Mary’s Parish Church and Haddington West Church were revealed at the beginning of 2022.
At that time, it was confirmed that eventually the two congregations would come under one full-time minister at St Mary’s.
No timescale was given for when any such move could take place.
A spokesperson for the Sidegate church gave an update in the church’s newsletter.
They said: “In order to prepare for the eventual union of the congregations, a basis of deferred union must first be drawn up.
“This is the procedure when both congregations have ministers inducted on unrestricted tenure, which is our situation in Haddington.
“The basis of deferred union sets out the specific practical arrangements required for the setting up of a new united congregation.
“Once the conditions arise where a union can take place, on the departure of one or both ministers, the deferred basis of union becomes the basis of union, without further amendment to what has been agreed and with the inclusion of a section on ministry.
“This means that when change in ministry occurs, the basic work has been done in advance and enables the union to take place more quickly.”
The Ministers and session clerks of the two congregations have already held a series of meetings with the Presbytery Clerk, Norman Smith and Presbytery Mission Planning Convener, Abigail Morrison.
The church spokesperson added: “It was proposed that we form a small group to take the work forward comprising Minister, session clerk, plus three elders from each congregation.
“Our three elders have been approved by our session and this group will meet in due course.
“This will help prepare the way for the eventual union.
“Once this process is underway, we will keep both congregations informed about progress.”