I've applied for a visitor's visa last week in Abu Dhabi, visa takes about a week but now urgently needing the passport to travel. Can I visit the embassy and request it back? will it affect my application?
I would start by emailing and calling the embassy to see if you can get your passport back. If that doesn't - then try visiting in person. There doesn't seem to be a good or easy process available for getting your passport back before it has been fully processed. People seem to run into problems when they try to do this.