74   Set off etc

(1)  Where, in an action (in this section called the principal action), a claim is made by way of set off, counterclaim or cross action, the claim, for the purposes of this Act:

(a)  is a separate action, and

(b)  is, as against a person against whom the claim is made, brought on the only or earlier of such of the following dates as are applicable:

(i)  the date on which the person becomes a party to the principal action, and

(ii)  the date on which the person becomes a party to the claim.

(2)  This section extends to a claim by way of set off made by a defendant under the Civil Procedure Act 2005, even if one or more of the debts giving rise to the set off became due and payable after the date on which the defendant became a party to the principal action, so long as at least one of those debts became due and payable on or before that date.