A nullity of marriage order granted in respect of a voidable marriage shall operate to annul the marriage only as respects any time after the order has been made final, and the marriage shall, notwithstanding the order, be treated as if it had existed up to that time.
Subsection (1) has effect in relation to a decree of nullity granted after 31 July 1971 as it has effect in relation to a nullity of marriage order, but with the substitution—
(a) for "order has been made final," of "decree has been made absolute," and
(b) for "notwithstanding the order," of "notwithstanding the decree,