172. The defendant may plead by defence any ground of law or fact which shows that the conclusions of the demand cannot be granted in whole or in part.
He may also in the same proceeding constitute himself cross-plaintiff in order to urge against the plaintiff any claim arising from the same source as the principal demand, or from a related source. The court remains seized of the cross demand notwithstanding discontinuance of the principal demand.
1965 (1st sess.), c. 80, a. 172; 1972, c. 70, s. 7.