Question

On June 2023, John loaned Php 500,000 from Mark, payable in 5 years. The loan agreement was duly notarized and stipulated an interest rate of 10% per annum. The loan agreement also included a clause stating that John waives his right to contest or question the validity of the loan.

In May 2025, John encountered financial problems and was unable to pay the loan amount. Mark, the lender, filed a complaint for collection of the entire loan amount plus interest. John argues that the clause stating his waiver of rights is invalid and unenforceable.

1. Discuss the legal effect of John's waiver of rights in relation to the loan agreement.
2. What arguments can John raise to support his claim that the waiver clause is invalid and unenforceable?
3. Citing applicable laws and jurisprudence, analyze the validity of the waiver clause and its enforceability in court.