Stephen Byers, MP for Wallsend, said parliamentary answers showed schools had lost an amount equivalent to employing 3,480 newly qualified teachers because ministers underestimated pupil numbers in 1993-94 by more than 39,000.
They had underestimated primary pupil numbers by nearly 47,000 and overestimated secondary pupils by 7,400, Mr Byers said. The money schools receive is based on pupil numbers, and the overall loss was pounds 69.6m.
The estimates of pupil numbers are taken from internal government documents obtained by Mr Byers. He said: 'Our schools and our children should not be punished because the Government got their figures wrong.'
A Department for Education spokeswoman said projecting pupil numbers was not an exact science and the department believed the underestimate was more like 28,000.
Mr Byers said if that were the case schools had still missed out on about pounds 30m.