H1B holder and application for advanced degree green card

[drspecialist]

Dear All
Please I have an enquiry about applying for 2nd prefrence (Advanced degree green card). I havea Physical Therapist on H1B visa valid since November 2009 but I have not started working in the USA yet due to family health isssue. Currently I am in the UK and one of the emplyers in USA willing to sponor me for 2nd preference (advanced degree) green card as I am working in the health system and have master degree as well.
My question now please:
I have been told that I can apply for the Green Card and this will not affect my H1B status, so is that true or wrong?
I have been told that I can apply for the green card even when I am now in the UK without a problem, but other people told me 'NO' I have to be in the USA currently and have worked for a while with the H1B visa and have earned some money so basically have W2 form showing paid tax? so pleae which is true as I am so confused
Thanks in advance

[supender]

don't be confused. the employer can file I-140 even when you are out of country. If u r UK born, you can get green card fast by consular processing and then join this employer on green card.