The proportion of people who trust charities has fallen by 10 percentage points over the past year, according to figures from the consultancy nfpSynergy.
A survey of 1,000 people by nfpSynergy, published today, found that 56 per cent of respondents said they trusted charities "quite a lot" or "a great deal", down from 66 per cent in 2013.
It is the second-lowest figure since July 2007 – when it was 42 per cent – and means that charities have fallen to seventh on the list of most trusted institutions, behind small businesses and the royal family for the first time.
Armed forces, trusted by 70 per cent of people, remained top of the poll. Political parties were bottom on 12 per cent.
Respondents were asked to say how much they trusted 24 institutions and types of organisation, including supermarkets, banks and newspapers, from "very little" to "a great deal".
Scouts and guides were third on the list, trusted quite a lot or a great deal by 64 per cent of people.
Twenty-eight per cent of people said they trusted the Fundraising Standards Board quite a lot or a great deal; 35 per cent said they trusted it not much or very little. Twenty-eight per cent had not heard of it.
Respondents were also asked to rate how much eight specific measures would reassure them about charities, including: "every charity’s accounts are on the Charity Commission website for anybody to see"; "we review all costs every year to make sure they are as low as possible"; and "nobody in our charity travels first-class on expenses".
The most popular answer was "every new charity has to be scrutinised by the Charity Commission before it is approved", which 70 per cent of respondents said they would find quite or very reassuring.
"The Charity Commission makes every charity say how many staff are paid £60,000 or more" scored lowest, with 60 per cent of people saying they would find it quite or very reassuring.
Joe Saxton, co-founder of nfpSynergy, said that trust in charities was "highly volatile and can never be taken for granted".
"Having seen a rise in trust in 2012 and 2013, it has fallen from 66 per cent to 56 per cent this year," he said. "That’s the bad news and it’s hard not to wonder whether the revelations over chief executive pay and some of the stories about alleged donations to terror groups in Syria have played their part."
He said the research showed that charities should "scream and shout" about how they are regulated in order to boost levels of trust.