One in four community groups in rural areas said the pandemic is threatening their future financial viability.

Such organisations have provided vital services in recent weeks, providing telephone support, checking on the elderly and vulnerable people and delivering food and medicines.

An umbrella body said it would have expected more of its 225 members to be under financial pressure.

It said bigger organisations are facing more problems than smaller ones.

That is because they tend to own a premises and employ full-time staff whereas the smaller organisations rely on a volunteer workforce.

The findings were in a survey for the Rural Community Network.

“Groups in rural communities have really stepped into the breach in terms of responding to need during the lockdown,” said policy officer Aidan Campbell.

“The government couldn’t have done it without them, but the concern has to be how long that can keep going.”

Almost four in 10 Britons volunteer, with the vast majority saying it benefits their mental health and acts as an antidote to loneliness, according to a survey of more than 10,000 people.

The survey, conducted by YouGov on behalf of the National Council for Voluntary Organisations (NCVO), involved 10,103 people aged over 18, the largest poll on the subject in more than a decade.

Of the respondents 77% said volunteering had improved their mental health, with just over half (53%) saying it had improved their physical health.

Young people were most likely to say volunteering had helped combat isolation, with 77% of 18- to 24-year-olds agreeing with this, compared with 68% of all ages and 76% of 25– to 34-year-olds.

 “There is an emerging body of evidence that suggests volunteering can improve your mental health and the language I have read is that it can help with depression, life satisfaction and wellbeing,” said Karl Wilding, NCVO’s policy and volunteering director.

“Broadly speaking, it helps as it is a social activity, and when you are doing things with others and groups that conviviality and connectedness is important,” he said, adding that it was most beneficial to people who didn’t have a partner or a job.

A 2017 study into Wildlife Trust volunteers found more than half those who started out with low mental health had improved after 12 weeks.

The NCVO survey found that 69% of respondents had volunteered at some point in their life, 38% having done so in the past year. Extrapolated over the entire adult population, this means more than 20 million people had given of their time at some point in the year.

The statistics revealed by the Guardian today are shocking. They must serve as a wake-up call to both the government and the third sector. Acevo has been warning for three years that charities are struggling to meet rising demand for their services while their income is falling. These figures not only confirm that trend, but demonstrate the scale of the financial challenge facing the sector. They show that many charities and community groups are facing the real threat of closure, with hugely damaging consequences for the beneficiaries and causes they serve.

The fact that close on 10% of voluntary organisations are questioning whether they will still exist in five years’ time should give everyone cause for concern. The impact of such a loss on local communities and the most vulnerable would be incalculable. Charities, community groups and other voluntary organisations often take years to build up, driven by the passion and energy of committed people. Once they have been allowed to disappear, they cannot simply be recreated when circumstances improve. And while too many of us sometimes take charities for granted, we would certainly notice the impact of their disappearance.