Five Doncaster churches could be closed down under new proposals.
The possible move has been outlined in a letter to all the Catholic churches in Doncaster, which are going out to consultation this week.
It would also see four of the church's Doncaster parishes merged as leaders try to deal with a fall in the number of priests available and falling congretations.
A letter to parishes from the Bishop of Hallam, the Rt Rev Ralph Heskett said: "In recent months, as you know, informal discussions have been taking place about the future of parishes across the Doncaster Deanery.
"In the light of these discussions, I have been presented with a strong proposal for the future structure of the Doncaster Deanery. Although this proposal is not 'set in stone', I do wish that this proposal be given very serious consideration."
He stated that the plans had been put forward because the number of people attending church regularly was declining and were getting older, putting financial pressure on them to maintain the buildings. He also cited a fall in the number of people coming forward to be active in the parish, and the increasing age of parish priests in the diocese.
He said: "I realise that the proposed changes will come very hard for some, and perhaps it will be no consolation to know that this restructuring is taking place across the diocese. Many personal and family stories / memories are bound up in a place or building. I do not underestimate the sense of loss that some will experience. Nonetheless we cannot be what we are called to be 'communities of missionary disciples' in the future if we do not act now."
He wants parish structures to be viable for the future.
The proposals would see:
* Cantley and Rossington amalgamate, with the closure of Finningley
* Mount Carmel and Kirk Sandall amalgamate with the closure of Armthorpe.
* Woodlands and Bentley merge, with the closure of Carcroft and Askern
* Edlngton and Maltby merge, with the closure of Balby.
The St Peters, Mexborough and Denaby Main, and Stainforth and Moorends parishes would not be changed.
Father Darren Reid, the parish priest for St Peters in Chains Church on Chequer Road said: "The Bishop of Hallam announced over the weekend of 9th and 10th June that the Doncaster Deanery is to enter a process of planning for the future.
"The process is ongoing, but is likely to involve the amalgamation and closure of some churches.
"This process has begun in a time when numbers attending Sunday Mass has declined. The age profile of those attending is often lacking younger adults.
"By the end of this year two priests in Doncaster will retire (both aged 80 years), and it is unlikely that they will be replaced. We wish to have Church structures in place that will be viable, and function well in the future."
The move has caused upset among some of Doncaster's churchgoers.
Rob Weston, who has been actively involved with the Catholic church in Armthorpe, and took part in a diocese synod in 2001 about re-organising the church parishes, said he was distressed by the plans, and the only reason he could see for the move was financial. He is calling on the bishop to think again.
He said: "This affects hundreds of people across the Doncaster area who are going to have a place that they have loved and cherished for years ripped from under their feet. I understand that there is a shortage of priests, but I think these are the wrong plans."
He said he felt the church would be better off looking for volunteers, volunteer clergy, and deacons to do more, to free priests to concentrate on work only they were qualified to do, like conducting mass.
He said he was concerned who people from the the churches which closed would get to mass
He added: "I know my mother would have no way of getting to another church."
John McCrystal , a former headteacher of the Catholic Our Lady of Sorrow Primary School, also in Armthorpe, was also concerned about the plan.
He said: "I was saddened and shocked to hear about the plans for changes throughout Doncaster
He added he thought was unfair to residents who had raised money to build Our Lady of Sorrow Church in Armthorpe to close it only around 50 years after it had been built.