5. Where an insurer, in relation to which an administration order has been made, subsequently goes into liquidation, sums due from the insurer to another party are not to be included in the account of mutual dealings rendered under rule 4.90 of the Insolvency Rules 1986 (mutual credit and set-off) if, at the time they became due, a petition had been presented to the court under section 9 of the 1986 Act (application for an administration order) in relation to the insurer.