Bad behaviour, such as bullying, is a leadership issue, one that new legislation or changes in regulations are unlikely to address.

Its eradication must be led from the top by everyone from senior politicians to team leaders by setting the right tone and demonstrating excellence every day.

Bad behaviour is prevalent: the Public and Commercial Services Union estimates 71% of staff have experienced bullying in the past three years. In addition, seven in ten nurses, midwives and nursing associates report having been bullied, harassed or abused in the past year alone, according to the Nursing and Midwifery Council.

But bullying is not illegal, depriving leaders of the option of legal sanctions against transgressors. Part of the problem seems to be that bad behaviour is ‘priced into' the culture, making it hard to address. Health bosses, for instance, still have to wrestle with consultant-as-god-syndrome. And all public sector leaders tend to defer to people who ‘get the job done', whatever it takes.

The problem is bad behaviour can be a continuum ranging from moodiness, through to throwing objects and physically threatening people – actual assault becomes a police matter.

Stamping out bad behaviour is a matter for everyone who performs a leadership role for three reasons.

First, leaders should be able to define workplace behaviour excellence so that all employees are clear about what is acceptable and unacceptable. They should also be able to put in place mechanisms whereby anomalies or inconsistencies are openly addressed to avoid one-rule-for-them, another-for-the-rest-of-us syndrome.

Parliamentarians have a responsibility to lead this charge and to demonstrate good behaviour in every action from issues they raise in the media to PMQs. Present political discourse seems to be careering towards the toxic end of the spectrum.

Second, leaders can and should set the tone. They determine through their actions and inactions, through passing remarks and public statements and through how they deal with unhelpful micro behaviours (eye-rolling, ignoring or undermining) what is acceptable or unacceptable. All too often it's easier to opt for a quiet life, letting obvious apparently minor transgressions go.

Finally, leaders have the power to define and call out errant behaviours in the moment. Publicly challenging those who bully others may be embarrassing but the cost of not doing so could be felt in the impact on others' mental health. Some might baulk at taking such actions, fearful of being accused of the same negative behaviours they are seeking to address. If so, there are other ways of doing this. But using this as a reason to do nothing, simply endorses ‘they didn't say no, so that means yes' and this perpetuates such behaviours.

Eradicating bad behaviour is long overdue. But all too often, leaders avoid addressing the obvious: what would good look like if there was no bad behaviour in the culture. A good starting would be to ask staff what they think by singling out the spaces where it actually takes place and fleshing out the challenges.

Take meetings, for instance. Should someone's access to air space or their level of public attention be determined by the content of their contribution rather than by unconscious biases, dress, or demeanour? Should there be a list of unhelpful behaviours on the wall of every meeting so that everyone can be clear about transgressions?

Or what about getting the job done? How should leaders exert pressure on members of staff to work at an optimal level? How should limits on such pressure be set – or calibrated? When does influence become intimidation? Navigating such cultural challenges are not easy – and may be locally determined. But present ambiguity is unhelpful. It can allow people prone to behaving badly to test the limits by relying on doubt, status, power, deference, fear and guilt to ensure nothing changes. It's far harder to tackle bullies who are very successful in the workplace than those who fail on a daily basis. (As it is for those in positions of power, influence or who are ostensibly indispensable.)

Tackling poisonous culture, like so many things in life, is reducible to a simple maxim: if you're not part of the solution, then you're probably part of the problem. People may just be frightened to say so.