Regularisation Of Contractual Workers

Sir!
If a contractual workers engaged through a contractor has been working for more than 240 days, is he/she entitled for regularisation by Principal Employer? Is there any Supreme Court Verdict or Law on this issue? Please quote.
Pradeep

If any contract employee proves that he has been working under the direct control and supervision of the Principal employer that the latter interferes in matters connected with wage negotiation and matters so related and the contract which exist or existed between the contractor and the principal employer has been sham or just for name sake, then he will be deemed to have right of regularisation. On the other hand, if the contract is not sham but genuine then no employee under the rolls of the contractor can claim regularisation even if he has been working for more than 240 days or even years.
Regards,
Madhu.T.K