Employees are increasingly being asked to take long periods of leave over the Christmas break, with many employers keen to see staff use up leave over the holiday period, an employment expert says.

The issue was highlighted when staff at consulting and accounting firm Deloitte complained of management instructions to take 12 of their 20 days of annual leave over Christmas.

"There was a real push to put pressure on a single employee to cash out their leave": ACTU secretary, Dave Oliver. Credit:AFR

Australian Human Resources Institute chairman Peter Wilson said directives to staff to use up leave represented a rising trend in some industries. ''Twelve [days] is the new record but it's probably not going to be a high watermark for long,'' he said.

Mr Wilson said between three and six days was the most common period of forced leave but employers were increasingly keen to balance the books by not allowing large banks of leave to accrue.