The Conservative leader, speaking to European internet business leaders at a conference in Hertfordshire organised by the internet search engine Google, said politicians should focus on "GWB" - general well being - at least as much as they did GDP or gross domestic product.

Describing the need to help people adjust to a fast changing, rapidly globalising world, Mr Cameron said thinking about the happiness of people was "the central political challenge of our times".

Departing from Margaret Thatcher's well-known questioning of the existence of something called "society", Mr Cameron said: "We do believe there is such a thing as society, it's just not the same thing as the state".

Mr Cameron called on all politicians to do more to consider the family, schools and work as places which had the capacity to deepen peoples' commitment to society and each other. Politicians, governments and private sector employers, he said, had to master the challenge of providing people with work that "adds to the quality of their lives".

"It's time that we admitted that there is more to life than money," he said. "We have to remember what makes people happy as well as stockmarkets rise," he added.

Citing examples of firms which had profited from providing their staff with better terms for flexible working, Mr Cameron said a Conservative government would aim to make the British public sector a model for progressive employment practices.

“We need to do this at the same time as showing clearly and unambiguously that these practices are raising productivity and improving outputs for the people who use and, through their taxes, pay for these vital public services,” he said.

Hailing the culture espoused by companies such as Innocent drinks and Howies clothing, Mr Cameron said: “It’s not just about T-shirts and jeans, it’s about a lifestyle and attitude that celebrates hope and hopes that through the power of ethical consumerism, business can change the world for the better.

“All these companies and more besides are expressing a profound dissatisfaction with rootless, rampaging globalisation and a passionate desire for capitalism with commitment, for work that has meaning and for relationships that are about more than just money and markets.”

On pensions, he said the Conservatives broadly supported Government proposals, or at least their direction, but he believed much more needed to be done to train an ageing workforce.

Taking questions, Mr Cameron said politicians had to grasp the potential of the internet to make politics and themselves relevant to the public and to hear the voices of electors. He praised the growth of internet access in the UK though there where still gaps to be filled. Asked whether he feared politicians having to turn themselves into celebrities or entertainers to reach a bored, uninterested public, he joked: "Entertainment has always been more entertaining than politics."

Asked whether proportional representation might not bring about a more effective form of democracy in Britain, Mr Cameron defended the representational strength of the first-past-the-post system with its direct connection to a locally elected and accountable Member of Parliament.

He said the 1997 Conservative defeat had been a "cathartic moment" in which people could see democracy at work as the removal vans rolled up to Number 10 Downing Street. Clearly, he said, he was hoping the removal van would be going the other way at the next election.

Click here for more from the Google Zeitgeist conference from Mousetrap, the Tech & Net weblog

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