RCW 19.72.140: Suretyship—Raising issue as defendant.

When any action is brought against two or more defendants upon a contract, any one or more of the defendants being surety for the others, the surety may, upon a written complaint to the court, cause the question of suretyship to be tried and determined upon the issues made by the parties at the trial of the cause, or at any time before or after the trial, or at a subsequent term, but such proceedings shall not affect the proceedings of the plaintiff.