Barking and Dagenham schools are “at risk” of losing more than £2million in the government’s National Funding Formula, according to predicted data.

Described as a “historic reform” by former education secretary Justine Greening, the formula, which comes into effect this month, sees an increase in spending on schools nationally by £1.3billion over the next two years.

But several education unions have been at pains to point out that the majority of schools are still running at a deficit longer term.

According to their figures – based on government data and Institute for Fiscal Studies calculations – the borough’s schools will have lost £6.5m between 2015 and 2020. That’s the equivalent of losing £176 per pupil over the same period.

The schools predicted to experience the biggest funding pinch in the period between 2015 and 2020 are Barking Abbey School (-£503,386) and Eastbury Community School (-£488,217)

Most of the schools losing out hardest – due to the number of pupils catered for – are secondaries, but William Bellamy Primary School (-£399,225), Eastbury Primary School (-£361,748) and Manor Infants’/Manor Longbridge School (-£318,786) are also set to be hit hard over the five-year period.

Paul Whiteman, general secretary of school leaders’ union of the National Association of Head Teachers (NAHT), said: “We desperately need the government to recognise that overall funding for schools is insufficient.

“It is totally unrealistic to ask school leaders to plan efficiently and effectively for the long term if they have no information about what will happen in as little as two years’ time.

“All schools need significant increases in funding. And as they fail to materialise, some school leaders could believe that the formula is the problem. Overall we will have a system that might be a bit fairer, but still won’t be transparent or sufficient enough to meet rising costs and growing needs.”

The two key factors behind the union’s calculations are government cash being reallocated across the country, and funding not rising with inflation.

According to the data, all 53 Barking and Dagenham schools are facing cuts, apart from Riverside Primary School, Parsloes Primary School, St Margaret’s Primary School and The Warren School.

To check how your school could be affected, visit schoolcuts.org.uk.