Hong Kong has its first sex workers' union for men, which has revealed that poverty and joblessness have forced more than 1,500 men to sell their bodies. The union claims the men - among them a 13-year-old boy and a 63-year-old former clerk - are subjected to police abuse and social discrimination. Midnight Blue, set up in August last year to help what they call the 'invisible' men, said unemployment had forced a growing number of school dropouts, secondary school leavers and middle-aged low-skilled labourers to sell sex. The men cater mainly to homosexual clients. With two social workers, the group offers an outreach service to men in massage parlours, cold-calls them and hands out condoms. They also provide classes on sex-work related laws, teach safe sex, offer Aids tests and host university talks to increase public understanding. Group co-founder Leo - a former worker of Ziteng, which helps women in the sex trade - said many people were unaware of male sex workers and their plight. 'They are more marginalised than female sex workers. People accept women selling sex, but not men. It is more difficult for them as they are not accepted. And they hide their identity from friends and families,' Leo said. Leo's co-worker, Chan Hau-leung, said social discrimination meant many of the men were defensive and it was difficult to reach them. The group believes half of the estimated 1,500 sex workers are locals, and the rest are mainlanders. Sex-work researcher Travis Kong Shiu-ki, an assistant professor of sociology at the University of Hong Kong, said the mainland sex workers often travelled between Shenzhen and Hong Kong. Many used to be farmers or had a background in manual work. He believed the individual traveller scheme introduced recently had brought more sex workers into Hong Kong. Leo attributes the rise in male sex workers to Hong Kong's economy, which focuses on knowledge and has forced many poorly educated men to take desperate measures. 'It is very sad. Now many jobs require a university degree. Many are Form Five graduates and middle-aged men who can't find a job and have to work as sex workers.' Leo said the oldest sex worker he had met was a 63-year-old former factory clerk who charges HK$100 to HK$200 for providing sex. He said that many of the men in their 40s were former factory workers who lost their jobs when their employers moved across the border. Others include former dish washers, cleaners and transport workers who can't find jobs, according to local sex worker Ah Ken. The 20-year-old blames the problem on poor wages in low-end jobs such as restaurant work. 'Some young ones work as shop salesmen and restaurant workers as a full-time job and become sex workers to support their income,' he said. Known as 'ducks', most of them find clients on internet chat rooms and through posting adverts in newspapers. Others work as escorts under an agent. Many others work in massage parlours. In Hong Kong, prostitution is not illegal, but soliciting clients is a crime. The unionists say police abuse is one problem affecting them as officers have stepped up their crackdown on male sex workers in the past two years. A police spokesman said they could not comment on the cases without details, adding that they had no arrest figures.