Kowloon Motor Bus drivers face 'enormous pressure' from passenger complaints and constant monitoring by their bosses, a staff union complained yesterday following the suicide of a driver. The claim came after driver Law Kam-pui, 41, plunged to his death from the bus depot in Tuen Mun on Thursday after he was reprimanded by his employers for jumping a red light. Chan How-chin, chairman of Kowloon Motor Bus Holdings Limited Staff Association, which represents more than 1,000 drivers, supervisors and technicians, said some complaints filed by passengers were unreasonable. He alleged that officers from the company's disciplinary unit questioned drivers without first checking complaints. 'This puts great pressure on us,' he said. But a KMB spokeswoman said every complaint from the public was studied before being referred to the disciplinary unit. About 40 per cent of complaints were screened out and no follow-up action taken, she said.