§ 144. Proof required. 1. In an action to annul a marriage, a final judgment annulling the marriage shall not be rendered by default for want of an appearance or pleading, or by consent, or upon a trial of an issue, without proof of the facts upon which the allegation of nullity is founded. Plaintiff shall prove that there has been no such cohabitation between the parties as would bar a judgment except that in an action under subdivision (c) of section one hundred forty the plaintiff may prove instead that the mental illness still continues.

2. In any action, whether or not contested, brought to annul a marriage, the declaration or confession of either party to the marriage is not alone sufficient as proof, but other satisfactory evidence of the facts must be produced.