Taxpayers have forked almost £17m on interim managers and consultants at Oxfordshire County Council in the past year, official papers show.

The disclosure - in confidential documents obtained by the Oxford Mail from a senior council source - has so infuriated Unison, which represents the majority of County Hall employees, it might ballot for strike action.

The figures in the report on interim managers and consultants shows £16,866,082 was spent between April last year and March this year.

However, County Hall said last night the amount spent on consultants alone was just £4.8m.

Interim managers were drafted in temporarily to fill vacancies when permanent staff were being recruited - and the total cost in 2005-6 was put at £910,000.

Of the remaining £11m in the report, the council said the service private firms provided was broader than just "consultancy work" - and saved the authority money in the long run.

Oxfordshire Unison branch secretary Mark Fysh said: "Consultants are being turned into the brains of the organisation. In terms of providing services like better school meals, smaller school classes and looking after the old absolutely nothing is being spent.

"This is purely cash in consultants' back pockets."

Money was spent across all council departments with £1.75m alone on computer experts implementing a financial system called SAP and training staff to use it.

The amount spent in the past financial year was discussed at a meeting between councillors and employees' representatives, from which the press and public were banned.

Head of human resources Steve Munn said: "Oxfordshire County Council didn't spend anything like this sum of money (£16.8m) on consultants. For April 2005 to March 2006 it spent £4.8m, less than one per cent of its budget."