Change employer with approved petition

I have an approved 1797 petition from an employer A, but still not gone for stamping.

I got a better offer from employer B who is ready to apply for amendment. But A threatens to cancel my petition as it has spent the fees/time on my petition.

  1. Is it possible for A to cancel my petition which is already approved

  2. Can A do anything else which could create a problem for B 's amendment or while visa stamping.

  3. I have the petition number and approved copy from A, Is this enough for B to file for amendment

  4. I am currently in UK, but I’ve applied H1B petition from India. Now that it is approved, can I apply for stamping from UK.

  5. Are there any problems/benefits of applying for stamping outside India?

Appreciate your response!

  1. Is it possible for A to cancel my petition which is already approved - Yes they can file to revoke H1.2. Can A do anything else which could create a problem for B 's amendment or while visa stamping. - No they can’t do much other then filing for revocation.3. I have the petition number and approved copy from A, Is this enough for B to file for amendment - Yes that is enough. Please go thru this … http://redbus2us.com/h1b-transfer-without-traveling-to-us-in-india-no-approval-notice-experience/4. I am currently in UK, but I’ve applied H1B petition from India. Now that it is approved, can I apply for stamping from UK. -You CAN, yes but It is generally advised to get the first H1 stamping for your home country(specially for Indian nationals) if you do not have a masters degree from US. Mostly because it is easier for background check specially in case of education verification…5. Are there any problems/benefits of applying for stamping outside India? - same as 4