THE organisation behind the national Census has been accused of making a monumental blunder - by mislaying more than 4,000 people.

Richmondshire District Council believes the Office of National Statistics has somehow misjudged its population by around eight per cent following last year's nationwide survey.

And the council fears that could cost it around £440,000 in Government grant - around nine per cent of its income.

According to the census figures the district's population is around 47,100, down some eight per cent from the 2000 mid-year estimate of 51,300.

However, the council insists the latter figure is more accurate and stresses that over the last ten years some 1,695 houses have been built across the district - and, using an average occupancy rate of 2.3 per household, that alone equates to 3,900 people.

The authority believes the problem stems from an error in assessing the military population at Catterick Garrison, Britain's biggest army base.

It points out that the base has expanded hugely over the last decade as part of the Ministry of Defence's Options for Change programme.

Chief executive Harry Tabiner said: "It seems clear to us that a common denominator in what we believe to be inaccurate population figures for a number of council areas is the presence of military establishments within their boundaries."

He added: "Bearing in mind that the military population at Catterick Garrison represents a very high proportion - approximately 15 per cent - of the total for Richmondshire, it is easy to see how the effect on our population has been skewed."

He has briefed local Tory MP William Hague on the situation and has also asked the sponsoring minister for the ONS, Ruth Kelly, to correct the error. Council members are also being urged to contact the Deputy Prime Minister's office.

However, a spokeswoman for the ONS said it was sticking by its figures - although it would discuss gievance with the council.

"In some areas there are differences between the earlier mid-year estimates and the Census figures - but it was those mid-year estimates that were wrong and army bases are taken fully into account," she said.