More than two-thirds of women working in football have experienced sexism in the workplace, according to a new survey which also found more than a third believed they were underpaid compared with men performing the same job.

The research lays bare the scale of the discrimination in the game, showing that of those who had experienced sexism in the workplace almost a third had witnessed women being told they were unable to do their job because of their gender.

Despite the trailblazing success of women like the Sunderland chief executive, Margaret Byrne, and West Ham United's vice-chair, Karren Brady, they remain very much in the minority. Brady has spoken often of the sexism she faced earlier in her career as Birmingham City managing director and the will required to succeed in a man's world.

Female match officials, such as the referee Sian Massey, have also experienced discrimination – most notably in the incident that resulted in Richard Keys and Andy Gray leaving BSkyB after being caught on tape off-camera mocking her.

But the Women in Football survey, which questioned 661 female coaches, match officials, administrators and others working in football, suggests that much of the discrimination within the industry remains unseen. A total of 35% of respondents said they were not paid equally compared with men in their workplace performing a similar role, and 28% said female employees within their organisation were unfairly treated.

More than a quarter felt they had been overlooked for promotion because of gender and well over half worried that their appearance was judged before their ability to do a job. Almost two-thirds believed football was less accommodating than other industries for working mothers.

"On my first day at work a senior figure in football slapped my bum when walking past," said one anonymous respondent. "I didn't want to make a complaint before I had even met the rest of my colleagues."

Another said: "You can't report someone every time someone says something derogatory as it's so commonplace."

Scores of female match officials and physios said there were practical impediments to doing their job, such as a lack of female changing rooms even at Premier League clubs. Others called for more diversity in senior roles in football and more female representation on the FA board and Council. The non-executive director Heather Rabbatts remains the only woman on the main FA board.

Rabbatts, the chair of the FA's inclusion and advisory board, said: "Women remain still significantly under-represented in executive and board positions in the sport industry. Surveys such as this help to focus all our attention and the FA, alongside all of the football bodies, are committed to tackling discrimination at all levels."

Karen Espelund, the most senior woman at Uefa and the first to join its executive committee, said progress was being made but there was much more to be done. "The Women in Football findings highlight some of the difficulties still faced by women working in football," she said. "We are making progress and new initiatives such as the Uefa leadership programme for women will undoubtedly play an important part but it's clear that we still have more work to do to ensure that women are best able to reach their full potential within our game."

At Chelsea, the club doctor, Eva Carneiro, is the only woman appointed in that role at a Premier League club. "Women want to be leaders, we just put them off as we go along," she told a Swedish FA medical conference this year. "In every programme I've watched in my life, the female doctor is either hyper-sexualised or she's not present. This needs to change. Women are discouraged at a young age.

"As a male you can aspire to having a successful professional life and a fulfilling personal life. Women are told that if they want to have both, at best it's going to be difficult and at worse it's going to be a disaster. Ninety percent of the mail I receive is from young women wanting to perform the same role. We need to tell them its possible and that their presence will improve results."