Advocates appeared:
For the Appellant(s) : Mr. Mehmood Umar Faruqui, AOR
For the Respondent(s): Mr. Purvish Jitendra Malkan, AOR Mr. Alok Kumar, Adv. Mrs. Dharita P. Malkan, Adv. Ms. Nandini Chhabra, Adv. Ms. Bhavna Sarkar, Adv. Ms. Neha Ambashtha, Adv. Ms. Deepanwita Priyanka, AOR

Based on the provided legal document, the key legal principles regarding the dishonour of cheque under Section 138 of the Negotiable Instruments Act are as follows:

1. The offence under Section 138 is only made out if the cheque dishonoured at the time of encashment represents a legally enforceable debt or liability on that date (!) (!) .

2. If the drawer makes a part payment after the cheque is issued but before it is encashed, such payment must be endorsed on the cheque as prescribed by law. Without this endorsement, the cheque does not represent a legally enforceable debt at the time of encashment, and therefore, the offence under Section 138 would not be attracted (!) (!) (!) .

3. Payments made prior to the issuance of the cheque, which are not acknowledged or endorsed on the cheque, do not affect the enforceability of the debt at the time of encashment. If the debt has been discharged or altered before the cheque is presented, the cheque no longer represents a legally enforceable debt, and the offence under Section 138 cannot be established (!) (!) .

4. When a cheque is issued as security, it is not automatically subject to Section 138 unless the conditions for dishonour are met at the time of encashment, i.e., the cheque must represent a legally enforceable debt at that time. The issuance of a security cheque does not preclude the possibility of the debt being discharged or altered before encashment (!) (!) .

5. The statutory notice issued under Section 138 must specify the amount due, which should correspond to the amount in the cheque, and must be issued within the prescribed time limits. An omnibus notice that does not specify the exact amount or does not reflect the part-payments made may be invalid. The demand in the notice must be for the actual amount represented in the cheque at the time of its presentation or encashment (!) (!) (!) .

6. The conditions in the provisos of Section 138 are additional safeguards that must be fulfilled for the offence to be established. These include timely presentation of the cheque, proper demand made within the statutory period, and failure to make payment within the prescribed time after demand (!) (!) .

7. Ultimately, if the cheque does not represent a legally enforceable debt at the time of dishonour—due to part payments made after the cheque was issued but before encashment, or due to other altered circumstances—the offence under Section 138 is not established, and the accused cannot be held liable for dishonour of the cheque (!) (!) .

In summary, the legal enforceability of the debt at the time of encashment is crucial in establishing the offence under Section 138. Payments made after the issuance of the cheque, unless properly endorsed, do not negate the offence if the cheque does not represent a valid debt at the time of dishonour.