The job looked good on paper – serving guests at an exclusive banquet in a City of London livery hall. The pay was good, too – £10.20 an hour, the London living wage and significantly more than the £7.05 for similar jobs. For Lucy, a 19-year-old corporate catering assistant, it was far too good an opportunity to turn down.

Later, she wished she had. The extra pay did not make up for the barrage of comments and bad behaviour, including persistent and unchecked harassment by a diner who made inappropriate sexual comments, asked personal questions and propositioned her for a threesome. “At some point he was ‘complimenting’ me and telling me I looked beautiful,” Lucy said.

“Then he was like: ‘Yeah I think my girlfriend would really like you. We’d both like you very much’. I was shocked and disgusted – and he knew how young I was.”

There was no escape. Lucy, who did not wish to reveal her surname, was assigned to his table, so she had to keep returning throughout the evening. He tried persistently to give her his phone number, ignoring her objections. “He wasn’t being discreet about it. He was doing that in front of all the other guests. All of them were just laughing. It was horrible.”

Secret filming of misbehaviour at the Presidents Club charity event in London’s Dorchester hotel. Photograph: FT/BBC

That evening was one of the worst that Lucy experienced at the lavish banquets and dinners thrown under the umbrella of the City of London and the Livery Companies – the city’s powerful network of male-dominated ancient trade guilds.

Last week the City found itself drawn into an incendiary row over harassment experienced by “hostesses” at last week’s Presidents Club annual dinner in Mayfair. The Bank of England launched an inquiry into how “afternoon tea” with its governor, Mark Carney, came to be auctioned, only to discover it was a hand-me-down from the Lord Mayor’s charity appeal. Of the 360 guests at the club, the vast majority were businessmen and investors operating within the Square Mile.

Questions are now being raised about the treatment of serving staff and hostesses at the opulent white and black-tie dinners, where hundreds of people gather each month in grand dining halls dotted around the City. “It is mostly men, and they’re members of the club, so there’s this sense of entitlement,” said Lucy. “I had no idea about where I could complain. It was never mentioned in training. None of it was talked about.”

A new draft code of conduct for members of the City of London Corporation – the Square Mile’s governing authority – makes no mention of harassment, sexual or otherwise. The code also appears to impose a three-month cut-off point for complaints to be made following an alleged incident.

Lucy says she felt trapped by her financial situation. “I didn’t really have a choice but to work there as they are one of the few places paying London living wage. But if I’m on a zero-hours contract, how do you think I’m being protected? I’m not. It would be super-easy for them to be like ‘sorry we don’t have any work for you’, which they definitely did for other people.”

According to Lucy, the sort of harassment she experienced is commonplace. But she claims the company she works for was more concerned with retaining clients and their lucrative contracts than protecting the welfare and dignity of their staff. “They don’t care about us. Even if most of us quit they’ll just hire more students,” she said. “The endless harassment is enabled by our precarious working conditions. It’s so easy to get the labour, and we’ve got no protection – nothing.”

For critics of the City, the code is a shocking example of how an influential sector of society is failing to show leadership. “It beggars belief that the City of London thinks it has no need of a sexual harassment workplace policy. But it is far from being alone in both failing to give contractual protection and dealing with the underlying problem,” said Sophie Walker, Women’s Equality Party leader.

A corporation spokesperson said: “Harassment of any kind is completely unacceptable in the City of London Corporation or anywhere else. Any reported allegations of harassment will be properly and robustly investigated.”

It is not only the City which finds its culture and practices under intense scrutiny this weekend. The guest list of the now infamous Presidents Club dinner featured a roll call of well-known bankers, entrepreneurs and celebrities. Of the 21 tables at the black-tie event, 10 were sponsored by property groups. Invited industry figures included Ian Hawksworth, chief executive of Capital & Counties, a FTSE 250-listed company; Paul White, chairman of real estate fund manager Frogmore; David Pears of the property magnate family and Gary Hersham, managing director of upmarket estate agents Beauchamp Estates. It is not known whether any of them attended.

In 2016 the property magazine Estates Gazette said the industry needed to clean up its act after prostitutes were seen to be doing “brisk business” at Mipim, a four-day networking event held in Cannes. “It wasn’t subtle and it wasn’t discreet – in fact, it could hardly have been more obvious,” the article said, pointing out that sex workers had used the event’s hashtag to attract business.

Liz Hamson, the editor of industry magazine Property Week, used her column last week to thunder at the Presidents Club event: “If there ever was a time and a place for such a men-only gathering, that time has passed. My hope is that it also marks the beginning of the end of the behaviour associated with it. A chill wind will be blowing through people’s Mipim plans.”

Meanwhile, the industry which supports such dinners and events has been trying to minimise the fallout from the Financial Times’ investigation.

Caroline Dandridge, the founder of the Artista agency that provided the hostesses for the Presidents Club function, and lists dozens of bluechip companies as clients, has gone to ground. The company’s offer to clients was apparent from its website, which featured pictures of women dressed in schoolgirl uniforms and hotpants. Dandridge has also posted videos of women posing on glitter balls and dancing in their underwear. The 55-year-old, who failed to respond to repeated inquiries from the Observer, has boasted of working with high-profile clients including luxury watchmakers Breitling, champagne house Möet Hennessy, Bentley, Barclays and the Economist.

But the firm’s former clients, when contacted by the Observer, were quick to distance themselves from Artista, including those who had been listed as providing testimonials. A typical response came from the aerospace company Honeywell, which said it did not have a record of working with the agency in recent years but was continuing to look into the matter.

Ascot racecourse – which was listed by Artista as saying its “girls” looked after guests “with the utmost charm and diligence” – said that it “does not use the firm directly but they have been used by third-party bookers at events from time to time”. The Economist did not respond to a request for comment.

One person willing to speak on Artista’s behalf was Nigel Greaves, owner of event stage specialists NGA Events and a friend of Dandridge, who described her as a “mother hen”. “There are boys and girls who can be hired for registration at conferences or handing out leaflets at exhibition stands,” he said of Artista. “They’re always very professional, very polite and well groomed, affable people. She [Dandridge] is very much a mother hen, in the sense that she looks after her staff. She is not one of those people who just hires and fires. She makes sure they do what is required but also ensures that nothing untoward is done to them.”

He didn’t believe the Presidents Club would have a major impact on the events scene, describing it as an isolated case. If the numbers are anything to go by, the bosses of Britain’s growing corporate hospitality industry will be hoping that he is right. The sector is now worth more than £1.2bn, according to trade body the Hotel Booking Agents Association. Within the sector’s ranks, a quick Google search for hostess agencies alone throws up a long list of companies with names like Exhibition Girls, Hostess World and Eye Candy, all offering databases full of attractive men and women to serve drinks and canapés and mingle with guests.

For Lucy, the future seems to be no more certain now than before the revelations about the Presidents Club. “You get talked at like you’re a piece of meat,” she said. “With men-only events it’s a safe haven for them. They’ve got no one to keep them in check. It’s really shitty. The work in itself is hard, you don’t get to rest, so if you get harassed on top, you don’t feel great about yourself.”