The SNP-run council is now demanding a public apology from Brian Wilson, the Education Minister, after Government statisticians included Gordonstoun, where 85 per cent of pupils had no Standard grade or Higher passes because they do GCSEs and A-levels. As a result 11 per cent of Moray pupils were said to have no SCE passes. Only Glasgow had a worse score, with 16.6 per cent.

Margo Howe, the council’s education convener, said this week that Scottish Office officials had misread the statistics and should not have included Gordonstoun in the official tally. The figures were published last week in a statistical bulletin on school-leavers’ qualifications over a 10-year period.

A Government spokesman said the survey had always included independent schools. The difficulty was that Gordonstoun had previously been included in figures for the former Grampian Region. “That is why its effect is more obvious,” he said.

Mrs Howe said that without the Gordonstoun figures Moray’s percentage of leavers with no qualifications was 3.9 per cent, one of the better scores in Scotland. “It is very difficult for us to get back the credibility we have lost over this, which has caused quite a stushie here. The statistics were so much out of kilter with all that our education department was saying.”

She insists the scale of the inaccuracy demands “an immediate and very public apology and correction”. Moray schools were “needlessly and misleadingly cast in a bad light”.

Mrs Howe told Mr Wilson: “It is accepted good practice for statisticians to double-check any aberrant figures. Such good professional practice would have resulted in contact with my department and the figures could have been amended appropriately.

“Additionally, it seems to be a product of a Thatcherite obsession in the civil service with league tables which results in such information being faxed to the press before any information is provided to education authorities. ”