Go back to old employer - will they need to file my labor and i140 again?

First of all, you are doing a great job helping people like us. I really appreciate it.
I am employed by consulting company X for 8 years and they have filed my H1B, and my i140 is approved for a while.

Company Y is my client and they have filed my H1 B based of I 140 from company X.

If I switch to Company Y to get a full time position, I should be good for next few years on basis of approved H1B

Company X said they will withdraw my I 140 - which could be the case so that they dont have to pay for taxes.
I understand that my I140 will still be valid and I can get the benefit out of it.
After 1 -2 years if I wish to go back to Company X will they need to file my labor and i140 again ?

If the old company does not withdraw the i140, they do not need to file it again when you join them again in future.

But I thought they cannot withdraw i140 since the rules have changed. Could you confirm if they do not need to file labor and i140 again?

Employer cannot withdraw i140 if you have worked for them for at-least 180 days after i140 approval.

Thanks AG, yes it’s past 180 days and company y is filed my H1 b based off company Xs approved I140

So if I decide to go back to company x, will they need to file my labor petition again?

Filing Labor again depends on the job profile that you join again with Company X.

If they still have the same job available as the PERM and i140 approved for, then there is no need to file it again.

Hey Anil, aren’t withdraw and revoke two different things. Employer can withdraw the I 140 but it cannot be revoked past 180 days.
If employer withdraws it after 180 days and it is not revoked, will going back to prev employer in that case, should they file new Perm and Labor Or just the I140 ?

If Employer withdraws it, then they have to redo everything starting with PERM.

Your point is correct but is only valid if you join any other Employer.