Coram Family and Childcare's annual Holiday Childcare Survey, found childcare provision to be patchy from area to area and the costs of accessing it increasing significantly during the school summer holidays.
Overall, just 31 per cent of local authorities said they had sufficient provision for everyone who needed it, and availability was even lower for children and families with specific needs.
Just 17 per cent of councils said they are able to provide enough holiday childcare for children with disabilities to meet their needs, while only 14 per cent reported having enough childcare for parents who work outside 9am-5pm.
The picture was not much better in rural areas - just 16 per cent reported full sufficiency although 38 per cent did not know whether there is enough provision available.
The government's ‘right to request' policy - introduced in 2016 to allow parents to request that their child's school provides childcare or opens up their facilities for another provider to do so - is also not having the desired effect; just four per cent of local authorities said the policy has had a positive effect on the availability of holiday childcare.
The survey also revealed that the average cost of holiday childcare has risen by three per cent since last summer, bringing the average weekly cost of holiday childcare to £138 - more than double the price parents pay for after-school clubs during term time.
Megan Jarvie, head of Coram Family and Childcare, called on the government to do more to support parents during the summer holidays.
"Working families are being left with few options this summer," she said. "The high price and low availability of childcare means that many struggle to stay in work, or can end up paying to work. Families need to see urgent action to fill the gaps in availability and financial support."
Jonathan Broadbery, National Day Nurseries Association's head of policy and external relations, agreed the lack of holiday childcare was a "serious concern" and called for councils to get a better understanding of the needs of families in their areas.
"We are seeing funding rates which don't meet the costs of providing childcare and if this continues nurseries and other providers won't be sustainable and the picture will get a lot worse."
Antoinette Bramble, chair of the Local Government Association's children and young people board, admitted that councils find it "increasingly difficult" to provide their own childcare schemes due to reductions in government grants.
"But [councils] are working closely with their communities and providers to support families in need of holiday childcare," she said. "This includes asking schools to stay open, encouraging providers to offer affordable schemes, and working with businesses to explore more flexible working hours for parents and carers.
"Unfortunately, we know many childcare providers are struggling, as funding for free early childcare fails to cover the costs of delivery."
She urged the government to use the upcoming Spending Review to provide investment into services to ensure parents and carers can access the right childcare when they need it.