A report from the National Education Union has revealed an increasing proportion of state-run schools in Bradford are running a deficit.
Subsequently, the union has warned that insufficient funding means schools across the country are struggling to make ends meet, as they are currently spending more than they are receiving.
Department for Education data shows 12 of the 125 local authority-run schools in Bradford finished the last financial year in deficit.
Comparatively, in 2013-14, only one out of the 188 schools that were then controlled by the local authority finished the year with a deficit
Regarding the new figures, Kevin Courtney, joint general secretary of the National Education Union, said: "The stark reality of [the reduced spending power] is that even with additional money coming in from April 2020, the vast majority of schools will still be struggling to live within their means.
"Government funding has simply not kept pace with inflation, nor the increase in pupil numbers, so what they now offer is completely insufficient to lift all schools out of financial jeopardy."
A Department for Education spokeswoman said: "This Government has announced the biggest funding boost for schools in a decade, giving every school more money for every child.
"This means that every school in the country can see per pupil funding rise in line with inflation next year, with all secondary schools receiving a minimum of £5,000 per pupil.”