The validity of the marriage is an issue separate from the enforceability of the prenuptial agreement.
If there was not procedural fairness in getting the prenuptial agreement (such as not disclosing all relevant information), the court may not enforce the agreement.
However, unless there is a statutory basis of invalidity, the parties are married. That statutory bases can be found at RCW 26.09.040. The text of the statutes are at http://apps.leg.wa.gov/RCW/default.aspx?cite=26.09 .
If you have an attorney, why aren't you reviewing your facts and options with your attorney?
The statute has a list of criteria the court is to use to determine if the marriage is valid. one of them is "force, duress, or fraud involving the essentials of marriage."
i suppose you could argue that, but for the pre-nup, you wouldn't have agreed to the marriage. if the pre-nup was fraudulent, then the grounds for entering the marriage were fraudulent.
frankly, i'm not really sure why you would do this, because you would still have to go through the divorce process to allocate assets/debts, parenting plan / order of child support. however, there might be religious reasons for preferring a decl. of invalidity over a decree of disso.
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