Ok,not on SN but need some wise advice.
I got new job (part time) and started in April.
It means a commute to London twice a week. It is high-pressured but largely status driven, rather than having a sense of achievement. I mean it is what you are and the position you hold that seems to be the reward rather than what you do.
The post also requires political impartiality. This just doesn't mean party political stuff, but not getting publicly involved in campaigns on issues which could be construed as 'political'.
This is a very big change for me. I am a VERY political person! I feel like I've been neutered 
My boss is very heirarchical but not actually very good and he has been taking work I have done for him (legal advice on complicated issues) and circulating it under his own name. He also always has his eye to the main chance which means he is clearly capable of dumping me like a ton of bricks when difficult issues arise - this has already happened once.
It became very clear this week that the plan is for me to do his work while he moves on to working on other projects (unspecified).
He is of that class and that type who thinks I am his dogsbody. But I am an experienced lawyer with a PhD - I am not 'The Help'.
I want to resign so I can focus on my freelance work, be mouthy and political and be myself again. 
Yes, I will lose a regular salary which was nice but I still have some freelance work.
The question is: I am now on hols for two weeks. Do I wait to tell him when I come back or give advance notice by email now? If I wait, I am still working from home when I return until the end of the month (and he is on hols) so I wouldn't get the chance to speak to him face to face until the end of Aug.
Preposterously I have to give 3 months notice even though I am on probation so this would mean a big delay.
What would you do in terms of resigning? I know email is not great but it gives him some warning.