15/01/2015 02:49 GMT | Updated 15/01/2015 05:59 GMT

Archbishops Justin Welby And John Sentamu Make Their Biggest Political Intervention Yet

The Church of England has labelled income inequality "evil" in a scathing assessment of the coalition, in which it questions how David Cameron has allowed entire communities to be "cast aside."

In one of the Church's biggest ever political interventions, timed to coincide with the general election campaign, the Archbishops of Canterbury and York said valuing communities on purely economic output was a "fundamental sin", and claimed Britain has become dominated by consumerism and selfishness.

In a video to launch the collection of essays in his new book Rock or Sand?, which includes a contribution from the Archbishop of Canterbury Justin Welby, the Archbishop of York, Dr John Sentamu, admitted the Church was making a political intervention but said it was not trying to be party political, despite remarks being clearly aimed at coalition policies.

Dr Sentamu said the UK faced a "deep, deep economic crisis" during the last four and-a-half years and said inequality trapped "hard-working" families on "poverty wages".

An extract from Archbishop Welby's essay, published in the Daily Telegraph, also criticises the "un-Christian" principle of of what is known as Social Darwinism - "every person for themselves", and said while London and the South East are growing economically, "entire cities are being cast aside" and left to decline.

In a separate interview with the Telegraph, Dr Sentamu criticised parties for focusing on voters in Middle England and appealing to the cult of the individual, giving rise to a society under the "rule of the jungle".

The Archbishop of York John Sentamu (L) talks to The Archbishop of Canterbury Justin Welby

He said: "Some people who read this book may ask themselves, 'Why should the church involve itself in politics?' Well the book itself is not about the church engaging itself in party politics but politics as far as I understand it has to do with public deliberations on how society should be governed. It if for the whole nation to engage itself in deliberations on how we should be governed."

Dr Sentamu criticised what he called "rampant consumerism and individualism" embodied by events such as Black Friday. "This marrying of justice and self-interest is deeply unfashionable in a political scene where parties rush to outdo each other in enticing and beguiling the swing vote of Middle England not with a vision of justice but with appeals to individual preference, interest and consumer choice," he told the paper.

"If it is the survival of the fittest that's what I call living in the jungle and I don't want to live in the jungle - this is supposed to be a civilised society.

"It is nothing to do with being socialist of whatever. What it has got to do with is, 'Is this how God created us?' Has he created us to be people who go to Black Friday to fight with each other because they want the biggest bargain? No, that's the rule of the jungle, we left that behind."

During a three and-a-half minute YouTube video, Dr Sentamu likened the UK economy to a household, claiming no one member should have "too much" when another had "too little".

He said: "The book addresses crucial questions about the moral principles that undergird the way Britain is governed. It is about building firm foundations for Britain's future and setting out the essential values we need to build a just, sustainable and compassionate society in which we can all participate and flourish.

"We need to rediscover the true meaning of the word economy - it means a household, a community whose members share responsibility for each other. The giant that must be slayed is income inequality - where some few have far too much and the many have too little."

It mirrors a similar intervention 30 years ago, when the Church of England published a report entitled Faith in the City: A Call to Action by Church and Nation, which highlighted social and economic inequality as a result of the political championing of the free market - and was also published under a Tory-led government.

The book is to be published next week with contributions from experts in economics, politics, and religion, including Labour peer Lord Adonis, Sir Philip Mawer and economist Andrew Sentance.