Nearly 500,000 bank workers in India, home to one of the world’s most robust outsourcing industries, walked off their jobs on Friday to protest against the planned outsourcing of their work to private domestic companies.

The one-day strike was in response to “continuing attacks on the banking industry and bank employees’ jobs and job security,” said the All India Bank Officer’s Association (AIBOA), one of the three labour unions organising the protest. Outsourcing in India’s banking industry would threaten 250,000 jobs, the unions said.