“Thanks,” I said to my friend before taking a first sip of the cheapest pint in central London. I was slouching in a dark corner of one of the dozen bars in parliament. It was past 10 at night, but the place was packed. “There are the Labour party people,” my friend said. “Over there are the Tories,” he added. “And there are the journalists.” Taking a second sip, I looked around, trying to avoid seeming conspicuous. “Everyone here looks the age of my students,” I told my friend. “Yeah. They’re mainly researchers working in MPs’ offices. Sometimes an MP comes down here,” he said. “Most just want a drink. But you have to watch out for a few of them.”

I had not thought about my friend’s offhand comment until stories began to emerge of sexual harassment by male politicians in Westminster. Looking at the growing list of allegations, I was shocked but not surprised. I spent two summers in Westminster with my colleague, Jo Silvester, interviewing dozens of MPs and parliament officials. We were frequently told that MPs’ offices are like “650 small businesses”.

And, as in most small businesses, basic personnel processes are accidental at best. A potential staffer can discover an “informal chat” is actually a job interview. Newly recruited staff members can feel bewildered because of lack of guidance. More established staff can find they are asked to do things that go far beyond their job description. When things go wrong, staff members have no clear processes they can use to register their complaints.

These problems are compounded by large power differentials between MPs and their staff. Some MPs think that being an elected official elevates them above the rules that apply to others serving the public. It is little wonder that some parliamentary staff spoke about their job as “member handling”.

Lurking just below this sense of invincibility is an equally troubling insecurity. MPs know they live in a world where power and loyalty is everything. Reshuffles and scandals can come from nowhere. They can end up shouldering others’ mistakes. And if they find themselves ousted by their constituents, building another career can be tough.

An absence of formal systems, big power differentials and endemic insecurity has made the House of Commons into the ideal hothouse for uncivil behaviour. No wonder the Labour MP Jess Phillips described parliament as “toxic”.

Westminster is not unusual. The structures in place in parliament mirror investment banks, elite law firms, top management consultancies and scientific labs. In each of these workplaces, you will find many ambitious young people relying on a few older, powerful, yet securely insecure individuals. They run their teams like private fiefdoms. Yes, there are HR departments, but they are usually an afterthought.

Uncivil workplaces are costly. They manufacture stress, anger, anxiety, ill-health, poor productivity, and low job satisfaction. They push people out and this increases recruitment and training costs. High turnover blows huge holes in an organisation’s collective memory. In parliament, this means we get lacklustre public scrutiny, worse laws, and poorer political representation. The toxic culture of parliament is one reason why successive UK governments are so successful at creating grand screw-ups which cost the taxpayer billions.

Theresa May has made a start at cleaning up parliament by introducing a code of conduct. But a new document is not enough to detoxify the Westminster bubble. We need to make MPs offices less like a collection of small businesses. This means politicians might swallow a bit of their own medicine and adopt the same kind of formal HR processes they have foisted on public service. One idea is to make MPs’ staff into civil servants rather than personal underlings.

We also need to ensure that people can speak up, and their voices will be heard. Introducing an anonymous reporting line or calling for people to come forward is not enough. Parliament needs to make people who speak out feel like they will be taken seriously and won’t face reprisals. To do this, parliament should encourage regular feedback from junior people, and ensure transparency about the feedback process. It should soften the symbols of power around Westminster, and shout about cases of when people created positive change.

Finally, we need to ensure parliament is a more diverse workplace. In her Good Parliament report, Sarah Childs, professor of politics and gender at Birkbeck, University of London, makes many suggestions about how this could be achieved. Three recommendations that need urgent consideration are: providing proper maternity leave; ensuring parliamentary hours are more regular and predictable; and providing transparency about who was and wasn’t selected as a political candidate. Doing these things would help to make parliament look a little more like a normal workplace.

Making parliament into a more diverse and civil workplace will take effort. MPs must all realise they are responsible. In the words of Childs, this means “MPs should acknowledge parliament does not just serve the preferences of individual politicians. They also have a collective responsibility as a parliament.”

• André Spicer is professor of organisational behaviour at the Cass Business School at City University London.