Hi,
Hope I'm doing this right as it's my first post...

I am applying for PhD positions right now and met with a possible supervisor a few months ago. He was very friendly, approachable and excited about my ideas (even though, in retrospect, my ideas were all over the place at the time). I've continued through the application process and here I am, a few days before submitting an application for funding and I think I want out. Although initially he was very helpful, his tone has changed recently and the last emails I opened from him were pretty rude and critical, accusing me of not considering his previous comments, though I had.

I'm trying to be grown up about this and realise that people have bad days etc but I'm worried sick that this could be a taste of what is to come if I pursue a PhD with him. How do I withdraw my interest without sounding as if I can't take criticism? I can take criticism, no problem but the tone bothered me a lot and I'm not convinced the criticism was well-founded.

Either way, I'd like to know how to email him politely to get out of the application process. Do I go through with the application and just not take up the studentship if I get it (seems slightly unethical...) or should I get out now. If so, what do I say?

Thanks!