The NUT and ATL have published a list of top 100 areas they say face the most severe funding cuts.
Ahead of the Autumn Statement next week, both unions are calling on the chancellor Philip Hammond to reverse the government’s policy of cutting funding per pupil in real terms.
The top five constituencies on the list are all in London: Bermondsey and Old Southwark, Hackney South and Shoreditch, Hackney North and Stoke Newington, Camberwell and Peckham, and Streatham.
The list also includes the constituencies of former education secretary Lucy Powell (20th), education secretary Justine Greening (27th), Labour leader Jeremy Corbyn (72nd), and Department for Education minister Edward Timpson (93rd).
This month, the NUT is organising a series of rallies to call on the government to change course on school funding. The first march and rally will be held tomorrow in London.
It comes after the unions launched an interactive map – schoolcuts.org.uk – of England’s schools which shows their estimate of how plans to redistribute funding would impact on individual institutions.
The formula used is based on the government’s spending plans, Institute for Fiscal Studies projections, rising inflation and other cost increases and the new funding formula proposed by the f40 group of local authorities.
Kevin Courtney, general secretary of the NUT, said: “The chancellor needs to heed the warning that schools cannot continue to give the education children and parents expect and deserve unless additional funding is given.
"There is no further room to manoeuvre, budgets have already been cut to the bone and all the sacrifices and compromises have been made.
"Schools simply cannot take another blow to already precarious finances. We need to invest in education. Failure to do so will be seriously letting a generation of children and young people down."
Mary Bousted, general secretary of the ATL, said: “We urge the government to do the right thing and fund schools adequately so that they don’t have to cut the subjects they teach and can pay to put a teacher in front of every class.
"Simply reallocating the existing schools budget won’t do. Virtually all schools would be worse off and it would hit the poorest children hardest.”
However, a Department for Education spokesperson said the list was "irresponsible scaremongering based on speculation".
They said: "It’s unfair and confusing for parents, pupils and schools themselves. We are due to publish a new fairer funding formula, and as the NUT and ATL admit, their speculative figures do not take that into account."