The inspectorate's early years statistics show that at the end of December last year there were 39,700 registered childminders in England, down by 1,000 on figures for the end of August. This is a three per cent fall and represents a rate of 8.2 childminders leaving a day.
Since September 2015, the number of registered childminders has dropped by 8,200 (17 per cent).
Early years groups say lack of funding is a key reason for the exodus and why so few people are looking to take up a childminding role.
A particular concern is the government's decision to axe childcare business grants at the end of this month.
Professional Association for Childcare and Early Years (Pacey) has said this has been a vital area of funding to help prospective childcarers with upfront investment in setting up their business.
A survey by Pacey last August found that underfunding for places under the government's 30 hours funded childcare scheme, is another issue affecting childminders. This found that 41 per cent saw their profits fall as a result of offering places through the scheme.
An additional concern is the length of time it takes to register, which can take up to six months, adds Pacey, which is to carry out research into falling childminder numbers.
"We have lost another 1,000 childminders in England at a time when demand for childcare has never been higher, and childminding should be thriving," said Pacey chief executive Liz Bayram.
"The continued drop in registered childminders is a major concern, so much so that we have now commissioned a team of researchers at University of Plymouth to identify what is causing this decline and, in particular, why fewer people are choosing childminding as a career. Its findings will inform both Pacey's future plans and its policy goals.
"We know people will not continue to childmind forever, with most doing so for between five and 10 years. The challenge is how to encourage new entrants to replace those who are leaving. The recent decision to end the childcare business grant for childminders has had a negative impact as will the continued registration delays at Ofsted.
"However, there are more fundamental issues that need addressing, notably sustainable funding for early education places; the right to receive this funding for related children; and the ongoing need to support parents to better understand the high quality that childminding offers."
Early Years Alliance chief executive Neil Leitch added: "The woeful underfunding of the early years sector is taking its toll on dedicated and passionate practitioners.
"Ongoing research by the Early Years Alliance shows a stressed, unappreciated and underpaid workforce so it is no surprise that Ofsted found childminder numbers are continuing to fall."