Mitigating factors in disciplinary procedures

I am in the middle of a disciplinary process with an employee for a gross misconduct issue, and he has asked me to look at mitigating factors. The investigation already found that there has been a breach of policy which falls within our definition of gross misconduct. Surely this means dismissal should be automatic? How do I handle it?

Jennifer O'Sullivan writes:

As part of the obligation to apply fair procedures in a disciplinary process, an employer must give full consideration to what would be a fair, reasonable and proportionate sanction given the specific circumstances of the disciplinary issue in question. The Employment Appeals Tribunal have been regularly critical of employers who