The school leaders’ union NAHT said that representatives would gather in Parliament Square on Tuesday afternoon, alongside parents and MPs, before marching to Downing Street.
Some 2,000 school leaders, staff and educators have signed a petition urging Mr Sunak to take action to provide “adequate funding” for council-run schools, which have been hit hard by the Covid-19 pandemic.
Campaigners warn that maintained nursery schools, many of which are situated in the most disadvantaged areas of England, need more support to address the impact of the pandemic on young children’s education.
Unions have said that some schools have been forced to cut staff and services due to lost income and additional Covid-19 costs, alongside a lack of certainty over the funding they will receive next year.
“Maintained nursery schools provide the highest quality education and care to children in some of the most disadvantaged parts of England,” the petition said.
“They support a high proportion of children with special educational needs who would otherwise have nowhere to go, and children on the early years pupil premium.
“They have a vital role to play supporting educational recovery and the levelling up agenda.”
It added: “We therefore call on you [Mr Sunak] to take urgent action to provide adequate funding for maintained nursery schools and support to address the impact of the pandemic.”
School staff are calling for resources “to put in place a long-term viable funding solution” ahead of Mr Sunak’s spending review which is expected later this month.
“Maintained nursery schools have been left in limbo for four years, under threat of closure,” Paul Whiteman, general secretary of school leaders' union NAHT, said.
“As we head towards the comprehensive spending review it is critical, now more than ever, that the chancellor delivers once and for all for the sector.”
In response to the petition, a Department for Education spokesperson insisted that ministers had put forward “unprecedented investment” for childcare in recent years.
“We've made an unprecedented investment in childcare over the past decade, spending more than £3.5bn in each of the past three years on our free childcare offers and increasing the hourly rate paid to councils above inflation for the past two years,” the spokesperson said.
“We are also making millions more available through our early years recovery work to level up children's outcomes.”
They added that council-run nursery schools provided “valuable services” and the government remained committed to their long-term funding.
Additional reporting by PA