Where on or after an insurer carrying on long term insurance business has wound up, or takes steps to wind up such business, and where the assets relating to such business have not been or are not sufficient to meet the liabilities subsisting under policies of long term insurance business issued by such insurer, then every holder of such a policy shall be entitled by action instituted in a court of competent jurisdiction to proceed against the private assets of each director of such insurer on or after that date, and recover any sum out-standing under such policy of insurance, where it has been proved that the winding up of the long term insurance business was due to the wilful negligence, fraud or dishonesty of each of those directors of the insurer.