Kent County Council staff sold more than 3,700 days of their holiday back to the authority last year at a cost of more than half a million pounds.

A total of 660 employees exercised their right to sell untaken holiday time between April 2008 and March 2009.

KCC says the leave sold – which is provided to employees as a lump sum and is not pensionable - was valued at £531,205. Over the same period, 227 county council staff also “bought” 1,360 days extra leave on top of their usual holiday entitlement, costing them £171,971.

Under the authority’s terms and conditions of employment, staff can take up to 10 days additional leave each year, provided it is approved by their managers. The entitlement to buy leave is part of what the authority describes as its commitment to help staff “achieve a healthy balance between their work and personal lives.”

The details of the buying and selling of leave were disclosed to the KM Group under the Freedom of Information Act. It follows our revelation that KCC chief executive Peter Gilroy had sold part of his leave entitlement for nearly £12,000 last year.

KCC says two other senior officers also sold leave in each of the last three years for a combined sum of nearly £18,000. The names of the two officers have not been disclosed under Data Protection legislation.

According to the data released, of the 660 staff selling holiday entitlement, 242 were from the children and families directorate and 174 staff working for adult social services. A total of 106 were in the chief executive’s directorate.

Where staff requests to buy leave are approved, their salaries are either reduced monthly over the year or can be paid for through a lump sum. In a statement, Cllr Roger Gough (Con), KCC cabinet member for communities, said: "We offer people some flexibility with their leave as part of our benefits package.

"However, this flexibility is discretionary and the council can turn down a request. The needs of the business and of services are always given top priority when it comes to reviewing requests to buying additional time off.

"In the same way, we insist that people working for us keep at least 20 days for time away from work before agreeing to sell any leave. With these safeguards in place, we are satisfied that we are able to offer something that staff value as an option but which does not, in any way, compromise our ability to deliver excellent public services.”