By Kim Jae-heun
Korean Air's three unions have called for the resignation of Cho Hyun-min, a marketing executive of the country's flagship carrier.
"We express our deep concern over her misconduct," the unions said in a joint statement.
This marks the first time for all three unions to reach this sort of an agreement.
Cho is the second daughter of Korean Air Chairman Cho Yang-ho.
She allegedly "yelled and threw water" at a manager of an advertising agency during a business meeting.
Cho, however, denied the allegation saying she did not throw water but only pushed him.
The marketing executive returned from her holiday in Da Nang, Vietnam, on Sunday and sent an email apologizing to all Korean Air staff.
A growing number of people have been filing a petition to strip Korean Air from being the country's "flagship carrier," and make it remove "Korean" from its corporate name.