The organisations - likened to a new breed of "air raid precautions" or "ARP" wardens from the Second World War - will team up to build the country's resilience in a catastrophe.

As part of a new National Security Strategy, Prime Minister Gordon Brown also revealed that the Government will publish for the first time a list of the risks faced by Britain, including possible numbers of fatalities in a range of disasters.

The strategy paper said the "risk register" would be issued in the summer, and would "enable communities to prepare better".

For example, it said the highest threat currently faced is an influenza-type pandemic which the Government believes could kill up to 750,000 people in the UK.

The second-highest risk is coastal flooding on the scale of the 1953 East Coast floods which claimed 300 lives, and which could result in the evacuation of hundreds of thousands of people.

The latest document set out moves by ministers to deal with a wide range of threats, including terrorism, nuclear attack, natural disasters such as extreme weather and flooding, international crime and cyber attacks.

People would volunteer to join their local civil protection network, run by town halls.

They would help evacuate elderly people in the event of a flood, for example, and could even play a role in the aftermath of a terrorist attack, the spokesman said.

The new risk register will be updated annually and may be available online.