England’s largest councils have called for a massive injection of government funds after saying they no longer had sufficient money to run vital frontline services, from children’s centres to rural bus routes.

The Conservative-dominated County Councils Network (CCN), which represents authorities covering nearly half the country’s population, said its members expected to make an extra £900m of cuts next year to balance their budgets.

It said councils would need to make “unpalatable” cuts to respond to the soaring demand for children’s social services and adult social care.

Roads, libraries, Sure Start centres and youth clubs, bus route subsidies, recycling centres, and drug and alcohol services were likely to face deep cuts and closures, while services charges would be increased or introduced, the CCN said.

Cllr Nicholas Rushton, CCN’s finance spokesman and the Conservative leader of Leicestershire county council, said the government needed to intervene with extra funds if county councils were to avoid unpopular cutbacks in 2018-19.

He said: “County authorities are in a serious and extremely challenging financial position. The further planned funding cuts and continued escalation of costs outside of our control will make this bad situation even worse. There is not enough money today to run vital services.”

The growing financial pressure on budgets would increase the risk of councils moving to a “core offer”, meaning services would be stripped to the legal minimum.

Northamptonshire county council, which is technically insolvent, has said it will set out proposals for core-offer cuts at the end of this month to try to fill a £60m hole in its accounts.

Several county councils have reported financial dire straits, including Somerset and Lancashire, while others, such as East Sussex, have warned they face bankruptcy within three years unless they make drastic cuts.

Last winter the government intervened with extra funds for social care to prevent a revolt by backbench Tory MPs incensed by cuts to funding in rural areas.

David Hodge is sending a strong message to central government. The Conservative chair of the County Councils’ Network (CCN) – a collective of the 36 counties in the UK – has set out to challenge the status quo. “I want to see funding for growth, and I won’t stop talking about it,” he says.

Hodge, who was appointed as chair of the network earlier this month and is also leader of Surrey county council, says the government needs to unshackle councils.

“Whitehall must allow localism to develop and flourish – otherwise there’s no point in it.”

At the same time he says the County Councils’ Network need to stop whinging and complaining. “It’s our job to offer solutions to government; alternatives and ideas.”

“My biggest concern as leader of the network and leader of my own council is how we can say to the government ‘we are about changing services and transforming through innovation’. I hope the network will become leaders in this as it is important to understand every service being paid for. Every one of us has a duty and a role to play working with each other to reduce costs and provide a better service.”