Can I refuse a grant position I was offered and still hope to work there in future? After an interview, I was offered a pre-doc grant for one year. Although I'm very interested in the research, I have other reasons to prefer staying in my current position: I think it would be easier for me to pursue the PhD I want from here.
Is it possible to kindly refuse the proposal and still hope to work with that group in the future, or would I burn bridges this way? If it is possible, how can I refuse the proposal without offending anyone?
Professionally, they should understand, if explained to them in a polite and respectful way. After all it is your life, and they need to respect your decision. Yes, it is disappointing, but it should not burn bridges - good people are not easy to find and they should be happy to keep in touch; who knows what the future brings.

However, if they were so disappointed that they would be indeed offended by your decision, then it is likely that there are other problems lying in wait for you at that group, anyway.