UK food and clothing retailer Marks and Spencer has hired a New York business guru to motivate its entire staff of 56,000 in a bid to boost the company’s sales.

Retail motivationist Mary Gober is running a series of day-long mass sessions for the staff this week at Birmingham’s National Exhibition Centre, reported The Guardian. Staff are attending the sessions 5,000 at a time.

Shopworkers’ union Usdaw has estimated that the events will cost £10m (US$17.7m), which it believes is a waste of money, the newspaper said. But M&S defended the move.

“We chose Mary Gober from six contenders – not because she was American but because she has an individualistic approach. The whole idea comes from the fact that M&S want a new, motivated, trained workforce with good careers … We are also training people in-store and have had 8,000 staff volunteering to become coaches and team leaders,” human resources director Keith Cameron was quoted by The Guardian as saying.