Dear All, thank you for your responses. I will try to answer each of the above comments one by one.
I am afraid due to confidential nature of the issue, I am unable to reproduce the clauses. It may eb safe to assume that they are standar clauses of 'Lock-in' and 'Termination upon Default'.
Mr. Ravi Kumar:
One of the default provision relates to delay in payment, as already mentioned in my question above. The agreement is in the form of a standing order for continued supply of materials. My client, the purchaser, needed to make payments periodically for the materials supplied. The agreement stipulated that if there was a delay in payment, the agreement could be terminated. It was stated to be terminated by the seller.
My initial line of argument was the same, (which is quite obvious too) that when delay was condoned earlier, then the seller should not be allowed to use this as an excuse to terminate the contract. However, upon further consultation, I was given to u/stand that this was not a bullet-proof defence. I am looking for some credible and substantial source to back up this line of argument.
I agree with you, and perhaps you have u/stood the issue and have hit the nail directly on the head. I think I will give your suggestion some more thought as it sounds quite credible.
Once again, thanks everyone, and any further comments would be wonderful.