"Party A" awards a contract for Material and Services to "Party B" - Who is Principal Employer?

"Party A" awards a contract for Material and Services to "Party B" on a Principal to Principal basis.
"Party B" enters an agreement with a contractor "Party C" for manpower supply.
"Party C" deploys its employees as contracts labour.
Party B is responsible for the supervision.
Services are rendered at the premises of Party A.
Query: Who is Principal employer.

Principal employer will remain A.
A has entered into contract with B to give supplies and B has subcontracted it with C.
The relationship between C and A is only though B and there is no privity of contract between C and A.
Was there any clause preventing subcontracting.

What is principal to principal basis?

Principal to principal contract means a contract where in both the people to the contract have entered into a contract in their own capacity with no agents in between.

Mr. Nathrao, There is no clause preventing subcontracting.

It would have been safe if no outsourcing was mentioned as a clause in the contract.
Notwithstanding this A has the liability a s principal employer.
All contracts must have certain vital details mentioned, depending on nature of contract.
Have a standard contract for such hiring contracts which cover you legally and is up to date as per legal provisions.

Dear Mr. Nathrao, I forgot to mention I am Party B in the scheme of things.
Thanks for your valuable inputs.
Best Regards