Thousands of charities across Britain rely on people power - the money they receive from public donations and the time given by volunteers.
Without the millions of pounds donated to good causes and the thousands of hours given by willing supporters to help the causes they care about, the work of charities would grind to a halt, be it helping the vulnerable, caring for the elderly, preserving our heritage or ensuring young people get the best start in life.
Britain is one of the most generous nations on earth, consistently in the top 10 of our World Giving Index.
But a new report we are publishing today lays bare the fact that the bulk of the people power that drives our charities is concentrated in a small minority of people. If you take together donations and time volunteered, we found that nine per cent of people are responsible for two-thirds of this social action in Britain.
And while there are a generous two thirds - 67 per cent - of people in the middle ground who do the remaining third of the charitable giving and volunteering, the fact is at nearly one in four people - 24 per cent - do little or nothing to help charities in this country.
That is perhaps not that surprising to anyone who has been involved with their local community, and has seen at first hand the well-known phenomenon that it always seems to be the same handful of people who are on all the committees, run all the events and can always be relied upon to donate a good prize for the raffle.
Obviously there will always be a minority of people who are particularly civic-minded, but the challenge for all of us in the charity world is not to relax in the knowledge that Britain is a charitable place, but to get those in the middle ground doing more and to motivate the zero givers to do something.
We wanted to start to understand what defines the most charitable people in the country, who make up the civic core of Britain. What sets them apart from other groups. And is there anything in the attitudes of those zero givers who do little or nothing for charity that might show us how to encourage more and more people to step forward and do something about the causes they really care about?
Our findings, based on a survey of people across the country, suggests that being part of the "civic core" - those most likely to be generous with their time and money - is associated with optimism, faith in human nature and concern for the environment. People in that group are more likely than others to strongly agree that there is a strong sense of community in Britain, more likely to feel that it is important to vote and more likely to say hello to people in the street in their neighbourhood.
In terms of attitudes to social action, 69% of the civic core strongly agree that it is important that people help others, whilst only 36% of the "zero givers" strongly agreed with the same statement. And it is their willingness to get involved that really sets apart members of the civic core from the rest - 75 per cent of them had volunteered in an organisation in the past year, compared to 18 per cent of the people in the middle ground.
In terms of attitudes to charities, there were also interesting differences. Those in the civic core are more likely to trust charities: 83 per cent of them believe that most charities are trustworthy, compared with only 51 per cent of the zero givers; this may be linked to the fact that they have a better understanding of the work that charities do: 90 per cent of the civic core said they understood this work, compared to 64 per cent of the zero givers.
Those who are most likely to give and volunteer are also likely to have friends who are involved in social causes and more likely to agree that they would say "hello" to people in the street. That means getting people giving is about building a stronger sense of society, as well as simply asking people for more time or more money.
The question is: Can we get people to take small steps towards building a more giving society? Getting involved in a community group, giving a neighbour a lift, making some cakes for a cake stall, going on a fun run with friends - all small things that take people on a step towards joining the most generous.
We have been pressing people to Back Britain's Charities in these uncertain times. Is it worth it? Of course there is strong debate about what voluntary organisations are for. Should they lobby for change, how should they be professionally organised? But we shouldn't lose sight of their ultimate aim, which is to change the world for the better.
That's why giving is central to the sort of country Britain is. And that is why it is important to keep asking how we can get people engaged and giving.