Actor Steve Coogan has warned that schools are at "crisis point" as he joined children outside Downing Street to call for government to plug a growing funding gap.
The 51-year-old star, along with Save Our Schools campaigners and MPs including Green Party co-leader, Caroline Lucas, delivered over 10,000 messages from young children to Number 10.
Youngsters from more than 60 primary schools across Brighton, Birmingham, Manchester, West Sussex and the Isle of Wight wrote positive notes about their school.
After delivering the messages the children, along with the Oscar nominated actor, MPs, teachers and parents gathered on the streets of Whitehall to sing a rendition of Sting's 1986 hit "message in a bottle".
The Spitting Image actor, whose own children attended state schools, said: "Schools are at a crisis point now. This is a real crisis that is having a material effect on the education of children right now."
The Trip star explained his concern that subjects such as, drama, music and sport will suffer and may be removed altogether if the cuts go ahead as they "are not deemed essential".
Mr Coogan added that the messages written by the children were very "moving" and show that it is "the children who are bearing the brunt" of the cuts.
One note from a young girl from Brighton said she loved the bikeability programme, an initiative set up by the Department for Transport to encourage people to ride bikes, because otherwise her household would not be able to afford one.
The MP for Brighton and Hove, Caroline Lucas, said: "Already, it's down to parents to do raffles to try to raise money for just basic things like glue and pencils and pens. This simply can't go on."
She added: "What we're saying to the Prime Minister is that the money is there. If she can find £1 billion for a deal with the DUP then she can certainly find it to fund our schools."
A Department for Education spokesman said: "We want to make sure all children, regardless of where they live or their background, have a world-class education that unlocks their talent and creates opportunity. Thanks to our reforms there are 1.8 million more children in schools rated good or outstanding than in 2010.
"The core schools budget is set to rise from £41bn in 2017-18 to over £42bn in 2019-20 with increasing pupil numbers.
"We have also consulted on a national funding formula for schools to make funding fairer. We received over 25,000 responses to the consultation, which we are analysing in detail and will respond to in due course."
Schools in England need to make £3 billion in savings by 2019/20, according to Government estimates, the National Audit Office (NAO), has said.
Education funding was a key election issue, with school leaders, parents and teaching unions all warning the nation's state schools are facing a severe squeeze on budgets, with many schools saying they will have to take action such as cutting staff and subjects.
Ministers have consistently argued that school funding in England is at record levels.
In their election manifesto, the Conservatives pledged to find an extra £4 billion for school funding over the next five years.