grievance

[co1]

can I resign my position having already raised a grievance?

[Lil O'lady]

I believe you can - and at the same time, you can pursue a grievance even if you have left, although it may become more difficult and may be an obstacle to your moving on psychologically.

Think about what you want out of the situation, and find out what outcome has resulted from other similar grievances in your organisation.

In many cases winning a grievance does not result in much - a line manager might be told thay have been very naughty and not to do it again. If you intend staying put, it is important to see the grievance through to flag up that there is a problem that needs properly sorting out.

[buildersmate]

A grievance process allows an employee to raise a serious problem with his/her manager, allowing independent hearing and review of the issues by more staff members than merely the immediate line manager.
(The grievance may or may not be with the behaviour or actions of the line manager.)
If you are resigning, I am not sure why you would want to do this. If its about money (owed) I can see you might. If it is about an alleged misconduct, I can see you might think you want to 'claer' your name if you are thinking about references - but organisations can always twist references anyway, so what's the point?

[buildersmate]

Singularly failed to answer the question!
yes, you can resign at any time, giving the required contractual notice period.