What is the effect of an agreement to extend time to the principal?

And, as this case involves extensions of the time period originally contemplated by the contract, these further statements of the law are apt: One type of variation of the principal contract which is of particular frequency and therefore concern are agreements which a creditor may enter into with the principal to allow the principal an extension of time in which to perform the guaranteed obligations, over the period of time that was originally contemplated in the principal contract. The effect of an agreement to extend time to the principal was stated by Best, C.J. in Philpot v. Bryant: A creditor by giving time to the principal debtor, inequity, destroys the obligation of sureties; and a court of equity will grant an injunction to restrain a creditor, who has given further time to the principal, from bringing an action against the surety……[5] The courts take the view that where the risk of liability is altered, it is for the surety to decide whether he will continue as a surety and bear the new risk of liability that arises from the restructured agreement. It is for this reason that the surety is entitled to be discharged if his consent is not obtained, as was pointed out by Lord Lyndhurst in Oakeley v. Pasheller: Now the principle of the law is, that where a creditor gives time to the principal debtor, there being a surety to secure payment of the debt, and does so without consent of, or communication with, the surety, he discharges the surety from liability, as he places him in a new situation, and exposes him to a risk and contingency to which he would not otherwise be liable.[6]