Changing Jobs after I140 approval - can I go back to ex comp. and resume the process

[darkknight]

I am in process of making a move from company A to B. I have my I-140 approved from Company A.

If a law is approved by government which only benefits people who are currently in I-140 approved state, can I go back to Company A and continue the immigration process? [ the assumption is that they haven't revoked the I140 application and I have good relationship with them]