Iain Duncan Smith has mocked the "dwindling relevance" of the Church of England.

The Work and Pensions Secretary said that when he heard bishops in the pre-election pastoral letter criticising "alienation and dwindling relevance" he assumed they were talking about their own congregations.

He told Sky News: "It is ironic that despite claiming to be non partisan they only produce these reports when conservatives are in government."

In fact the pastoral letter was unprecedented, and while the bishops did say it was time to move on from the Conservative Thatcherite polices, they also said it was time to move on from the Labour style of governments such as Atlee's.

Duncan Smith said: "I simply ask the question, where were the bishops when the last government crashed the economy, borrowed record sums, saw income inequality rise to record levels, while piling debts on the backs of our children?"

The Church of England's 52-page manifesto from the bishops calls for an end of "politics as an extension of consumerism" and also criticises Trident. The bishops voice concerns about poverty, hunger and an "ugly undercurrent of racism" which goes against Christian teaching.

The prime minister, a practising Anglican and like the Archbishop of Canterbury an old Etonian, had earlier also criticised the bishops and insisted the economy had "genuine growth, real jobs and real security".