London (CNN)Around seven in 10 LGBT people have suffered some form of sexual harassment at work, according to an alarming study highlighting a "hidden problem" in British workplaces.
Unwelcome jokes and comments or questions of a sexual nature were the most-reported forms of abuse, with nearly half of all LGBT workers reporting such behavior, according to the study by the Trades Union Congress (TUC).
Around one in six said they had received unwanted emails or pornographic images, and one in eight LGBT women even reported being seriously sexually assaulted or raped at work.
Most respondents did not tell their employers about the harassment, the study found, with some refusing to do so for fear of being "outed" at work. Its authors are urging new legislation to protect LGBT workers.
"This research reveals a hidden epidemic," TUC General Secretary Frances O'Grady said in a statement. "In 2019 LGBT people should be safe and supported at work, but instead they're experiencing shockingly high levels of sexual harassment and assault."
The study was released on May 17, the International Day Against Homophobia, Transphobia and Biphobia.
It found that LGBT women are more likely to experience unwelcome touching at work, with 35% -- more than in one three -- experiencing such advances, compared to 16% of men.
Black and minority ethnic (BME) women, and disabled people of both genders, are particularly victimized. More than half (54%) of LGBT BME women said they had experienced unwanted touching at work, and exactly half of disabled women said the same. Around a quarter of women in both categories reported serious sexual assault or rape.
Disabled men were also more likely than non-disabled men to suffer abuse, according to the research, with one in five reporting serious sexual assault.
The study calls on government to enact "a mandatory duty for employers to protect workers from all forms of harassment," and a statutory code of practice on sexual harassment. It has also urged employers to review their existing policies and conduct training for all employees.
"Workplace culture needs to change," said O'Grady. "No one should think that a colleague being LGBT is an invitation for sexualized comments or inappropriate questions -- let alone serious acts of assault."
A spokesman for the Government Equalities Office said: "It is appalling LGBT people are suffering this harassment. Workplaces should be safe, supportive environments for everybody.
"The government will consult shortly on how we can strengthen and clarify existing laws on third-party harassment, as well as making sure employers fully understand their legal responsibility to protect their staff," he added.