Time off for interview

[M1SSUNDERSTOOD]

Hi I have an interview tomorrow whilst at work and it's an internal vacancy so same site. Anyway it's not same department and due to current work issues, I was planning to tell my line manager I have a work related matter to attend to and need to meet my union rep (conveniently at time of interview!) I have had talks with the union hence my looking for a new job so don't think this is so far from true

I don't want my line manager to know I am going for an interview for various reasons and also it's too late now to suddenly announce I have one! WWYD?

Sorry should have mentioned I haven't seen my line
manage since I got very short notice of interview.

I would tell the truth if this is within the same organisation then your line manager will possibly find out about it anyway surely?? The people conducting the interview may even be in touch with him/her?

I would also tell the truth - in my company you have to tell your line manager before you even apply for an internal vacancy - they may well have already asked for a reference?

Thanks for advice. I am not sure why I feel reluctant. I know they don't take up references unless you are offered the job.