The Archbishop of York today delivered a fierce warning over the pursuit of power as the Church of England prepared to debate a massive centralisation of power into the hands of senior clergy.

Preaching at York Minster at the Eucharist for members of the General Synod, Dr John Sentamu told them that they were in danger of forgetting their priorities.

The attempted power grab, considered to be a way of cutting costs, comes as Synod members are being asked to take a demand back to parishes for a doubling of donations to finance a pensions black hole.

Dr Sentamu said: "The big priority for all of us is an unceasing renewal of commitment to Christ. Sometimes in the complexity of the activities of the Church we are so busy with committees, synods, administration and making the wheels go round that we are in danger of forgetting that none of these things matters, if it is carried out by people who have not been with Christ before they have been with others."

He added: "The idols of earthly wealth and power, the blessings people make for themselves, which are widely worshipped and highly exalted, degrade their devotees."

The Synod will today discuss a proposal to axe bishops and other senior clergy posts so the number of top-level clerics reflects the fall in full-time stipendiary clergy. There are now about 8,000 stipendiary clergy, a fall of about a quarter over two decades.

There are currently about 110 episcopal posts including the 44 diocesan bishops in the Church of England. The rest are suffragan or assistant bishops.

Other senior clergy posts include between 100 and 110 archdeacons and 42 cathedral deans as well as cathedral canons.

A briefing note prepared by the Bradford Diocesan Synod said the Church Commissioners spent £7.3 million in maintaining diocesan bishops' houses in 2008 and £14.5 million in grants for bishops' support staff, office and working costs.

Together with deans and canons of cathedrals and archdeacons they make up a body of senior staff that has remained largely unchanged in number for 50 years.

However, in the same period the number of junior clergy has plummeted, with parishes merged throughout the country and some clergy ministering to half a dozen or more country churches, racing between churches on Sunday mornings to pack in as many Eucharists and morning prayer services as possible.

But bishops who will fight the proposed cuts say their workload has increased in recent years, in part because of the need to implement an increasing body of new legislation.

They also say they are responsible for recruiting and managing the rest of the clergy, including a body of unpaid volunteer priests who now make up more than a quarter of the Church's workforce.

Bishop of Lincoln Dr John Saxbee said: "A bishop's job is to make sure that there is appropriate ministerial cover.

"Some of that will be stipendiary, that is paid, [and] some of it will be part time or voluntary.

"Now, all of them look to the bishop, so perhaps our workload is not looking like it's going to decline any time soon."

Another proposal is to increase the minimum retirement age of clergy from 65 to 68 in order to reduce the pensions bill.

The current full service pension for clergy - earned after 40 years - is £13,093 a year with a lump sum of £39,279.

The Church Commissioners, who manage the Church of England's investments, has been hit by the recession and the value of its portfolio shrank to £4.4 billion during 2008 compared with £5.7 billion in 2007.