Poor working relationships continue to dog the UK workplace, according to the IRS survey.
The two most common problems giving rise to formal complaints by employees were breakdowns in the relationship with their line manager, and breakdowns in relations with one or more colleagues.
The 133 employers who gave a figure reported dealing with 2,519 grievances in the past two years. Some of these incidents have fed through into changes in HR policies, with respondents reporting that they had amended their approaches to relationships at work, flexible working and dress codes.
But employers reported that grievances about all forms of discrimination were relatively rare.
Two-thirds said that complaints of race or sex discrimination never arose in their organisation, and just 10% reported having to deal with such issues anything other than infrequently.