Ministers must protect funding for state-run nurseries in England or risk seeing schools close, Conservative MPs have warned.
Children with disabilities and special educational needs would be among those most affected, they said.
The schools will lose almost £60m a year from 2020 unless action is taken.
The Department for Education said the nurseries made a valuable contribution but funding decisions would be made at the Spending Review.
Education select committee chairman Robert Halfon told the Today programme Treasury "bean-counters" would store up huge problems if the schools were not protected.
Conservative ministerial aide Craig Tracey and Chichester MP Gillian Keegan said they had raised the issue with ministers.
England has 400 maintained nursery schools, which are owned and directly paid-for by the state.
They have to hire better-qualified staff than private nurseries, and often teach and care for children with disabilities and special education needs. The majority are based in disadvantaged areas.
The Education Secretary Damian Hinds has identified programmes run in state-run nurseries as assets in improving social mobility - staging a media event in a Luton school in April - but some are already struggling to stay open.
Carole Jacques, who runs a nursery in Norwich, said they had to phone print companies begging for paper for children to draw on after money ran out.
Ministers provided extra money for the schools from 2017 after a shake-up of funding left some nurseries worried they would close. But the funding supplement agreed then runs out in 2020. The government has given no assurances about what will happen after this date.
Ms Jacques said her school would definitely close without the funding, as did Amanda King who runs two nursery schools in Warwickshire.
She said her schools were already losing £60 a week for every child with special needs they accepted.
Her MP Craig Tracey said there would be "huge consequences" if the schools closed, and he didn't know what would happen to children there with special educational needs as private nurseries had no obligation to take them.
Gillian Keegan said she was very concerned, adding: "2020 is only 18 months away. You need to start planning if you're not going to have a job in 18 months."
Fellow Tory MP William Wragg supports the push to maintain funding.
'No premature decisions'
Asked about the possibility of closing her schools, King said: "At the end of the day if the schools close and the places aren't there I don't know where the children will go and it's hard not to feel like you've failed."
A majority of the schools expect to run deficit budgets next year, according to a survey from an All Party Parliamentary Group supporting nurseries.
Labour MP Lucy Powell - who chairs the group - is to host the education secretary at a school in her Manchester Central constituency.
The children's minister Nadhim Zahawi said maintained nursery schools made a valuable contribution and the government also supported low-income families with free childcare.
He said: "I regularly meet with maintained nursery school leaders and we continue to work closely together to better understand the value these nurseries offer, so I would urge councils not to make premature decisions on the future of these nurseries as this work continues."
Decisions on future funding would be taken as part of the next Spending Review, he added.
Read on the BBC: https://www.bbc.co.uk/news/uk-politics-44691948