During the course of a heated argument, a manager told an employee:
"You can’t do the bloody job anyway." He responded by resigning and
claiming constructive dismissal.
There is an implied term in contracts of employment that the employers will not, without reasonable and proper cause, conduct themselves in a manner calculated or likely to destroy or seriously damage the relationship of confidence and trust between the employer and employee.
More information is available here: https://www.personneltoday.com/hr/trust-me-im-an-implied-term/