Research shows a clear link between social interaction and increased longevity, the meeting was told. But more than one million people aged over 65 say they are often or always lonely.

Every local council is to receive guidance on how to measure levels of loneliness and people at risk of loneliness in their area, Care Services Minister Paul Burstow announced.

Councils, responsible for public health from April 2013, will be urged to conduct an audit of health and care services and identify how they can help reduce levels of isolation.

Mr Burstow said: “Loneliness is the great unspoken public health issue. Research suggests it is more harmful to health than obesity and that there is a 50 per cent reduction in mortality if you have a strong social network.

“If we do nothing, these people are going to turn up in our accident and emergency departments and care homes at great cost to society and loss to the individuals concerned.

“Research has shown that loneliness can be as harmful to your health as alcohol and tobacco, but we also know that people who have day- to-day contact live longer and healthier lives. The Government is working with the Campaign to End Loneliness to raise awareness about just how important even a simple phone call or visit can be to someone’s health.”