How do I tell my current job if I don't get a promotion I'm leaving in the next few weeks?

I have an interview at another hospital before my shift on Friday.

Because of it, I'll be wearing a suit and tie. I can leave the suit/tıe in the car but it's going to be obvious I did something.

At the same time I applied for the lab supervisor role and I don't believe I'm in legitimate contention.

Should i even say anything? I've been here for years and it honestly hurts they not only won't listen to why I believe I'd be a good fit but won't even bother to just let me know it's not going to happen (I told the lab manager, I won't take it personally, please just let me know).

I suspect I'm probably the only applicant and they've gone overboard advertising the position since then.

Edit:

I've worked all 3 shifts, helped with linearity and validations, done all the maintenance, have prior experience (over a decade), work in every department including Microbiology plate reading and Blood Bank. Come in every time I'm asked, I even draw blood and I'm the only person to do legal alcohols for the most part.

If they dont want me, I doubt there's anything left for me to advance here or prove I'm capable.

Jobadvisor:

Given your situation, it's understandable to feel frustrated and undervalued. Here's how you can approach the situation:

Regarding the interview:

• Dress code: If you're concerned about your appearance, consider wearing a more casual but professional outfit. A blazer or a nice shirt with dress pants can look polished without raising too many eyebrows.
• Explanation: If someone asks about your attire, a simple and honest explanation like "I have an appointment later today" should suffice. You don't need to elaborate on the details of the interview.

Regarding the promotion:

• Don't say anything: If you haven't received a definitive answer about the promotion by Friday, it's best to avoid bringing it up. Assuming you're not selected, your actions might speak louder than words. Your departure will likely convey your dissatisfaction with the situation.
• Resignation letter: Once you accept the new position, draft a concise resignation letter. Keep it professional and focused on your decision to pursue a new opportunity. You don't need to delve into the reasons for leaving, especially if you haven't received official feedback on the promotion.

Additional considerations:

• Professionalism: Maintain a professional demeanor throughout the process. Avoid burning bridges or engaging in negative conversations with colleagues.
• Focus on the future: Channel your energy into the new opportunity. This is a chance to advance your career and find a workplace that values your skills and contributions.

Remember, your worth is not solely defined by a promotion. Your decision to leave is a testament to your self-worth and your pursuit of a better opportunity.