I am a software developer at a large corporation in the UK which I have worked for for 3 and a half years. For the last year I have been working on a fairly large and important project which is just about coming to a close. I would say I was pivotal to the completion of this project and want to see it through to the end.
I've been unhappy with my job for a while and have raised my issues with management several times. Chief complaints have been lack of pay rises, lack of training, and not being able to advance my career. I recently worked out that taking inflation into account, I earn less today than I did when I started.
I have been interviewing recently and just received an offer. It's a little bit lower than I was asking (by £500) but I'm still probably going to accept it. I have another two interviews next week which I want to attend to see what kind of offers they might have.
However, given my current position on this project, and I'm getting asked what my availability is for future work, I feel like I should give my manager a heads-up that I will be leaving, even though I haven't formally accepted an offer yet. Should I?