Immigrant visa?
Answer:
It is your Green Card which allows you to come and go as you please. If you need to leave and come back before you get it you must apply for advance parole. This is by no means guaranteed. Usually they are reserved for deaths or terminal illness, stuff like that. Please deal with the paperwork today. You are already cutting it a bit fine.
u re not writing where do u have visa - to usa or uk? if expiring visa is to uk and u intend to come back after it is expired - of course u won't be able to return. if expiring visa is to usa u have to exit usa till the end of visa date, if u intend to prolong your visa in usa u can't leave usa - u have to stay there till the day they make the decision whether they re going to prolong u your visa for staying in usa
stay away there are too many already
Coming back to the UK will be fine. But check about returning to the USA after that if your Visa has expired by that point and your green card isn't through by that time
here are your Dutys & Rights
http://www.uscis.gov/portal/site/uscis/m...
The immigration information post by website user , MyTend.com not guarantee correctness