The men, who are employed by a local sub-contractor, seem particularly unimpressed. Three or four in the front row, dressed in day-glo vests, are slumped in their chairs, staring at the floor. They look languid and sullen, like a gang of guilty schoolboys being admonished by the headmaster.
The lecture on the unpredictability of women continues: "Many people say to me, 'Lots of girls like to get wolf-whistles.' I know that's the case, but they don't go round with a plaque that says, 'Please whistle at me'. It's only afterwards that you know if they like it - and I only get feedback from the ones that don't."
When it comes to the sort of behaviour the Nineties female will or won't tolerate, the Anglo-American cable company Diamond Cable is taking no risks. Which is why Paul Niles lectures every new batch of workers about a strict code of non-sexist conduct.
In the past three years, Diamond Cable has been less than happy with its employees' behaviour towards women. As a result, it has sacked four of its own workers, along with two from subcontracting firms who have wolf-whistled or shouted crude remarks.
"There must be some of you who see a need for this," reasons Niles at the end of the talk. Silence from the men. "I mean, would you like your daughters to be subjected to remarks and whistles?" The silence deepens. Induction over, they troop out scowling.
The session seems to reveal as much about the gulf between management and workers as it does between men and women, and this bastion of male chauvinism isn't receptive, especially to a supercilious speech from its seniors. "Most women are flattered anyway," insists one workman, builders bottom hanging over his trousers. "Do you agree with the policy?" I ask another, who displays a similar expanse of bare flesh around his midriff. "I couldn't care less, love. It's just a PR job to keep the client happy."
Now engaged in a pounds 320m project to lay cable for the Independent Television Commission, Diamond Cable is digging up hundreds of roads in and around Nottingham. All 1,200 employees at Diamond Cable are made aware that disobeying its non-sexist policy can result in the sack. As well as forbidding sexist behaviour, swearing on site and causing "annoyance and distress" to the public, the men are not allowed to wear torn clothing or to work bare-chested.
This policy owes less to a PC-conscious management than to aggressive American-style marketing. "Everyone realises the need to interface well with the public," says Niles. "When we construct in an area, the sites are splashed with Diamond Cable signs, so people know it's us. We can't afford to present the wrong image to potential clients."
Witnessing the general cynicism in the morning induction, it's hard to imagine the cable-layers taking this corporate zeal to heart. When Niles reminds them, rather patronisingly, that, "I've got 1,200 of you guys out in the field and each one of you can ensure we sell cable by the way you conduct yourselves", the response is less than enthusiastic. But afterwards, I am assured that at least while on site, the men are the model of decency and self-restraint.
Later in the afternoon, in the sweltering heat and without the watchful eye of management, I decide to find out how much of Niles's lecture has sunk into this collective male psyche. Choosing a residential area in south Nottingham, densely populated with cable men, I began my search for the re-constructed construction worker.
Dressed in whistle-at-me boots with zips up the back, black velvet hot- pants and a black T-shirt, I stroll (or rather stagger) down the top of a busy road, smiling inanely. It's not a very convincing act, especially when I trip over the kerb in full view of three men digging up the pavement. Niles would be proud of them. They take absolutely no notice.
Two of the men look up but only to smile cautiously and then carry on with their work. I turn the corner and three more - the Diamond Cable logo emblazoned on their shirts - steadfastly shovel the ground as a mother and daughter walk by.
Following close behind them, I find a response which is more of a return to form. "Whoah-hey, darling - let me carry your shopping bags, they look heavy enough," one shouts, adding, "now I know why it was worth getting out of bed this morning." This group has clearly slipped through the corporate PC net.
On my way back past them, the spirited remarks continue. "Ohhh, you can bump into me if you like," chirps one, his mates tittering with approval. Stepping gingerly over his shovel, I ask him if he's aware that his bosses have a strict policy that forbids sexist remarks. "Oh yeah, but it's rubbish," he says, unconcerned that I am a reporter. "I mean, we're never insulting - most girls enjoy it. It's always complimentary." Isn't he scared of losing his job? "I don't believe what we say would cause any female to complain," he laughs.
His assumption - that all women are flattered by male attention however crude or unprovoked - appeared to be shared by all the workers at the morning session. Not a single man in the room put his hand up when Niles asked them if they agreed with Diamond Cable's policy. "What harm can the odd whistle cause?" three or four men asked me afterwards.
But now the company views women as potential cable TV consumers, they'll do anything not to offend this lucrative half of the market. "At the end of the day, you don't condone that sort of behaviour and assume there's nothing you can do about it," says Niles, determined to stamp out sexism in the name of sales. "Otherwise, we'd never make progress anywhere, would we?"