In-country application while one is in progress

[asp87]

I submitted an in-time application for leave to remain (skilled worker route) in the UK. However, I have not booked an appointment as I await a decision on my ATAS, which is now required to continue in my current job as per the new rules wef. May 2021.
I am now offered another job which does not require ATAS. The new employer will give the CoS after their pre-employment checks. Can I submit another Leave to Remain application with that, while the first one is still in progress?

I'll be happy to provide any further details, if needed.

[manci]

Can I submit another Leave to Remain application with that, while the first one is still in progress?

No, you can only have one immigration application in progress. If yoi submit a second application it will vary (supersede) the first application.

[asp87]

If yoi submit a second application it will vary (supersede) the first application.

Does that mean I can submit another application which would render the first application invalid?
In that case, that may have implications on my right to continue working for my current employer. Is that correct?

[ywlgy]

You cannot have two CoS assigned to you at the same time. You will need to ask your current employer to withdraw your CoS (which is not used because the case is not decided) before the new employer can assign theirs to you.