Senior Tories have condemned the nation-wide campaign, which will culminate next Sunday in a service at Manchester Cathedral addressed by the Bishop of Manchester.
Church Action on Poverty is not a formal part of the Church of England but describes itself as a "body in association with the Council of Churches for Britain and Ireland".
In the past it has organised meetings and talks, including one attended by the Social Security minister, Alistair Burt, on the fringe of the Conservative party conference.
A resource pack, sponsored by the public-service union Unison, has been sent to members around the country, and the national co-ordinator, Paul Goggins, said "prayers will be offered in hundreds of churches across the country to call to mind the problems of people out of work and on low pay.
The material sent out by the group includes ideas for services and notes for possible sermons which relate to the issues of pay. They include discussion on the position of Britain's "so-called fat cats", the directors of privatised utilities.
One senior Tory privately described the initiative as "outrageous". A former minister, Tim Yeo, said the information put out by the group was "tendentious". The row poses a potential dilemma for the Conservative party Chairman, Dr Brian Mawhinney, who is a member of the Synod of the Church of England.
Mr Yeo, a Conservative member of the Commons employment select committee, said: "It is using the socialist and trade-union agenda and cloaking it in Christian garments. It is diverting attention from what is important, which is that the absolute level of wealth is higher than it was 50 years ago.
"At a time when unemployment is still rising in Europe, 'Unemployment Sunday' seems to be doing nothing to address the real causes of either unemployment or poverty".
Mr Goggins said the campaign was a way for the churches to demonstrate their concern over unemployment.
He said: "Prayer clearly is one way, pastoral care is another, as is expressing a political concern that we need to change the direction and urgency from the politicians to tackle the fact that many people are out of work".