Thousands of smaller charities face a “slow death”, experts fear, amid declining donations and limited grants.

The cancellation of all participation events since March has seen overall donations to non-NHS charities drop by 46 per cent on a leading fundraising site.

But analysis by the BBC has found that smaller charities - without the reserve levels of their larger counterparts - are at far greater risk of having to cease operating entirely.

The leader of the Charities Aid Foundation (CAF) said the declining income from collection tins, charity shops and community events such as fetes and raffles had already hit the incomes of smaller operations by “hundreds of millions of pounds”.

Even though he said overall giving in 2020 was up by £800m compared to 2019 - the majority of those funds were absorbed by NHS charities.

Meanwhile, a poll carried out among 580 charity bosses in April found only a third had enough funds to meet running costs for the next three months.

Since then, many have been able to access part of a £750m support package released by the government for the not-for-profit sector - or some of a further £300m released by philanthropic bodies.

But many of the grants, charity leaders say, cover just six months of operational costs.

The Small Charities Coalition says parts of the sector face a “slow death”, the true scale of which will not be realised until early next year when that grant funding runs out.

Public polling also suggests particular types of charity are at greater risk.

Results from YouGov show the nature of giving has shifted since March towards hospitals and NHS charities and away from those dealing with homelessness, disability and animal welfare.

The Charities Aid Foundation (CAF) provides services and assistance to UK and international charities and their donors. It produces the yearly UK Giving report, which estimates the overall amount given to charities by the public.

Neil Heslop, chief executive, of CAF said: “The sector as a whole has been hit and the fundamental paradox they face is one of spiralling demand amidst a time of collapsing income.

“The British people have responded with extraordinary generosity. The totality of giving was over and above what we would normally expect in the year through to June.

“I think Captain Tom was a great example. His very personal response was in response to a massive, overwhelming media campaign in the early days of the pandemic.

“The message of ‘protect the NHS’ spawned a huge reaction and Captain Tom very much brought the British public with him in raising awareness of the value of the charities that complement the work of the NHS.

“That translated into NHS charities and hospitals themselves seeing a huge upsurge in support and that’s been wonderful to see.

“The challenge has really been for many other charities, especially the smaller ones that do not have much by way of reserves, that saw their normal fundraising drives completely shut down.

“They now find themselves at risk of shutting down because of all those sponsored runs and walks that were cancelled, the collection tins that bring in spare change at the rail station, all those small amounts of money collected at spring fetes for so many good, local causes that add up to hundreds of millions of pounds.

“The lost revenues from charity shops is unlikely to be replaced and for many shops, that means upwards of £25,000 a month that is gone from their budget.

“It’s important to remember that even small charities that rely on an army of volunteers to deliver their services all still have to pay the rent and the electric bill at the end of the month and those funds just aren’t there right now.

“What has been challenging is that some stalwarts have, including some of our biggest charities such as Cancer Research UK, conversely had a drop in fundraising and are stepping back operations.

“The sector as a whole is under massive pressure. Some of those charities do not have the cash reserves or resilience to ride out the storm.

“It’s worth remembering that smaller and mid-sized charities are the vast majority of the 200,000 plus across the UK and they are the backbone of so many communities.

“There is a very significant danger that the landscape changed and has changed forever as a result of the pandemic.

“It’s obviously critical that the population continues with that generosity, but also important that the government provides transitional support by increasing Gift Aid.

“The government has provided £750 million.

“That’s a significant amount of support and they have partnered with various organisations, including the CAF, to deliver that.

“We are making a case for further and continued support in a variety of forms.

“The nature of the change to the charity sector is genuinely enormous. Without all of us putting our shoulder to the wheel, there is a risk that, over the next year or two, our sector will be changed permanently and that would be a tragedy,” he added.

The Small Charities Commission provides information, advice and support to around 14,000 small charities across the UK.

Rita Chadha, chief executive of the Small Charities Coalition said: “With smaller charities being the focus of the emergency funds they have got some access to that money.

“But nearly all of the funding is a six-month emergency grant.

“Most of the grants came out at the beginning of June. At the moment there is a fear about the long term because there’s just not that certainty.

“In the run up to the next financial year we anticipate people will be asking us: ‘how do we let people go?’ and ‘how do we wind down a charity?’”

“The real pinch point will be next year when these charities officially start closing .

“It’s a slow death. Many of our charities are already having to decrease their operations already. They are telling us they are having to turn people away when demand for them is increasing.

“A domestic abuse charity I spoke to was having two referrals a day. They’re now having 20.

“Their programmes and activities tend to last for two years. If they take in someone today they don’t know whether they will be able to see them through the whole programme.

“Services are changing. People are finding things they have used for years and years are disappearing overnight.

“The government feels like it has to tackle covid entirely on its own - when all the resources at a local level are locked in charities. If you are not allowing them to amplify their services it will cost more money further down the road.

“Something like increasing Gift Aid to 30 per cent, that’s a nominal cost to the Exchequer, but would make a big difference to a small charity,” she added.