Calls by the activist Gina Miller for the Charity Commission to be abolished are based on "bad ideas" and "an incorrect reading of charity law", sector figures have said.
In an interview in the Financial Times newspaper, Miller said charities should be run like businesses, without separate regulation, and hinted that she knew of further safeguarding problems in the sector that had not yet come to light.
She called for the rich to give more to smaller charities, but added that the commission should stop new charities from registering if similar organisations already existed.
Miller has long criticised the sector, to the latter's consternation. In 2015, her charity the True and Fair Foundation published a report that claimed one in five charities spent less than half of their income on charitable activities. The following year it published another calling for an inquiry into the efficiency of the sector.
Both reports were criticised by the sector for alleged misrepresentation and inaccuracy.
In the interview published this week, Miller is quoted as saying: "There shouldn’t actually be a regulator, in my view, because [a charity is] just a different type of business."
She argued that regulating charities as businesses would increase scrutiny on areas such as overheads, executive pay and safeguarding, according to the FT, adding that "the job of a charity is to do yourself out of a job; that is it. It’s not complicated."
Miller said that if she were to produce a report on the sector’s safeguarding issues "the sector would be in such trouble", but instead she was working behind the scenes to improve things.
There was a lack of collaboration among charities, which viewed each other as competitors, she said, and the proliferation of charities duplicating each others’ work was encouraged by "lawyers, the accountants and philanthropy advisers", hoping to profit from administration fees.
In a statement, a Charity Commission spokeswoman said: "Robust, independent research tells us that the public value charity regulation.
"People’s attitudes towards charity vary, but almost everyone expects charities to demonstrate a higher standard of conduct and behaviour than other organisations and expect the commission as regulator to hold charities to account against those expectations.
"So Ms Miller’s view that charities should be treated as for-profit businesses is out of step with the vast majority of the British public, on whose support and confidence charities rely."
On Twitter, Karl Wilding, director of public policy and volunteering at the National Council for Voluntary Organisations, said: "Miller’s argument is based on an incorrect reading of charity law. It’s not simply about relief of the poor."
He told Third Sector: "Gina Miller is asking legitimate questions, but the conclusions that she draws are profoundly wrong. The statement that charities are just another form of business is a fundamental misunderstanding of why charities exist and how they work.
"And her idea that charities should aim ‘do yourself out of a job’ ignores much of what we are about.
"Would society be better off if the Ramblers, Kentish Town City Farm or St John Ambulance closed? I would welcome the opportunity to work with Ms Miller to identify how we can best help the causes that we all care about."
Kristiana Wrixon, head of policy at the sector leaders body Acevo, tweeted that she was not attacking Miller personally but said she "strongly disagreed" with Miller’s views.
On the idea that charities should all aim to put themselves out of business, Wrixon said: "It depends on what kind of charity you are: yes if you deal with homelessness, no if you are the Guides."
David Floyd, managing director of the social change research CIC Social Spider, tweeted: "Sadly, there's lots of people who have bad ideas about charities expressed in banal sweeping statements but (while admirable in others ways) Gina Miller is the UK market leader in bad ideas about charities that are simultaneously banal and internally contradictory."