Nurseries and childminders are being forced to charge parents for meals, trips and nappies due to a funding shortfall for a new Government childcare scheme, a survey suggests.
Mums and dads are being made to "pay the price" for Government under-funding of a flagship initiative to provide 30-hours of free care to three and four-year-olds in England, according to the Pre-School Learning Alliance.
A survey of its members found that around a third (36% of those polled) of nurseries and childminders offering the 30-hours were delivering them "completely free" - meaning that parents do not pay for extra hours or other goods and services.
The 30-hours offer was introduced last September.
The Government argued that it will be investing around £6 billion a year by 2020 in childcare.
It added that Government funding is not intended to cover costs of meals or other services, but that while nurseries can charge parents for extra, this cannot be a condition of their child's place.
The survey, which questioned 1,662 nurseries, pre-schools and childminders in England, and was first reported by the BBC, found that around a third (36%) are delivering fully free places to some families, but not all, while 28% were offering no fully free places.
Around a third (37%) of those polled said that they introduced, or increased charges for additional goods and services as a result of the 30-hour offer.
Of those that said they had brought in, or raised charges, 80% said they had done so for meals and snacks, 10% for nappies and 32% for trips.
Around 35% of all of those offering the 30-hours said they have increased their fees for non-Government funded hours.
Overall, three-quarters of all Alliance members surveyed said they are offering 30-hours places.
Alliance chief executive Neil Leitch said: "Respondents have laid out in black and white that the 30-hours policy is simply not working, with a continued lack of adequate funding leaving many with no option but to pass the funding shortfall on to parents.
"This has left parents to pay the price for Government underfunding through often unexpected charges for things like nappies, food and trips, while the Government continues to claim that it's delivering on its promise of 'free' childcare."
Purnima Tanuku, chief executive of National Day Nurseries Association (NDNA) said the findings were "worrying".
"The Government needs to be honest with providers and parents that 30-hours funded childcare is not 'free'," she said.
"There is a significant shortfall between Government funding rates and the cost to nurseries of providing childcare."
She added: "In asking for charges for meals and other extras, nurseries find themselves in a very difficult position. They need to make these charges to remain sustainable but the DfE guidelines state that these payments must be voluntary. Nurseries should not be put in this position."
A Department for Education spokeswoman said: "We are investing a record amount of around £6 billion every year by 2020 in childcare and have doubled the free childcare available to working parents to 30 hours a week, saving them up to £5,000 a year per child.
"Providers can choose whether to offer 30 hours and what pattern of days and hours they offer parents. We have always been clear that Government funding is not intended to cover the costs of meals or additional services. However, while providers can charge parents for additional extras, this cannot be a condition of the child's place."