Should I disclose why I quit to prospective employers?

Dear Jean,
Well done for being a person of integrity. Companies should have corporate values which must be adhered to by both managers and employees. In addition to technical skills, during recruitment, there is an attempt to bring on-board candidates whose values closely mirror those of the organisation.
However, the fact that the company you’re exiting allows your supervisor to get away with the issues you complain about is a clear indication that there is no clarity on the value proposition of the organisation. It’s not always that our personal values are aligned to our employer’s values, however, if the misalignment is too wide, makes it impossible for you to work and to get peace of mind, then it would be advisable to leave.
For example, managers who expect employees to engage in illegal activities like bribery and other forms of corruption.
I hope you had the opportunity for an exit interview before you quit so as to provide feedback to the organisation. This will be of great help to the staff who choose to remain and most probably “weed” out the rogue manager.
If your organisation has a whistle-blowing policy, this is a great opportunity to make use of it.
When you get an opportunity to be interviewed, choose the point at which you disclose why you left your previous employer wisely.
Don’t volunteer the information unless you are asked. Respond by stating that your values were not aligned with those of your previous employer and you resigned on principle. Desist from giving unnecessary details. Remember if you are seen to be a vindictive individual, your prospects of getting a job might diminish. Focus on the issue not the manager.
Be encouraged that you will get an employer who appreciates you in due time and whose values are closely aligned to yours.

Jane Muiruri, Senior HR Manager-NMG