The Bishop of Truro in Cornwall has admitted that "the parish church today is under real threat".
Speaking on Saturday to members of Truro Diocesan Synod, Bishop Philip Mounstephen said the key threats were "an ageing demographic, declining congregations, the burden of maintaining buildings, the struggle to engage with missing generations, and declining income".
"Those are real and serious threats which require real and serious responses," he said.
But he also stressed he was "certainly not blaming anyone for this state of affairs".
"This is really no one's fault. The forces that have led to this state of affairs have been in play for at least 150 years," he said.
The bishop spoke about the Save the Parish campaign launched in London in August ahead of elections to the CofE's parliament, the General Synod.
"It was launched to counter what its organisers perceive to be a centralised plan to do away with the parish system," Bishop Mounstephen said.
He told synod members that he and the area bishop of St Germans, Hugh Nelson, wrote to clergy when Save the Parish launched, saying: "We want to assure you that there is no central plan to undermine the parish system or to side-line the ministry of clergy. (And even if there were nationally, there would not be in this diocese!) And nor is there any such plan."
But, he added in his presidential address to the synod that his "concern with the 'Save the Parish' movement is not principally that it is reacting to what I believe to be a non-existing threat".
"I'm much more concerned that it might distract us from those very real threats that I mentioned just now," he said.
Truro Diocese, which includes around 300 churches in 200 parishes, many of them rural, has the oldest congregations of any diocese in the CofE, he said.
The diocese also experienced a sharper fall in income during the Covid pandemic than any other CofE diocese.
Nearly all frontline parish clergy in Cornwall are serving multiple churches. Bishop Mounstephen reported that the costs of clergy housing and stipends - or salaries - "outstripped by some way" the financial contributions that most local clusters of parish churches in deaneries were making.
"In some cases by very large sums indeed," he said.
"Again I don't want to attribute blame, but equally we must recognise that that is simply not a sustainable situation.
"None of us would imagine that such a huge shortfall between income and expenditure would be acceptable in a business or in a family's finances.
"None of us would see that as acceptable in the finances of a parish. Nor is it an acceptable situation in the life of our diocese.
"And I would be failing in my duty if I did not ensure we addressed it."
Formerly head of Church Mission Society, Philip Mounstephen became Bishop of Truro in 2018.