(1) The contribution conditions for disability benefit are -
(a) that the claimant has qualifying contributions in respect of not less than 39 contribution weeks in the period between his entry into insurance and the day for which the benefit is claimed, and
(b) that the claimant has qualifying contributions or credited contributions in respect of not less than 39 contribution weeks, of which at least 13 must be qualifying contributions, in the last complete contribution year before the beginning of the benefit year which includes the day for which the benefit is claimed, and
(c) that the claimant has prescribed reckonable weekly earnings in excess of a prescribed amount in the prescribed period.
(2) In the case of any claim for disability benefit where the period of interruption of employment commenced before the 6th day of April, 1987, subsection (1)(a) shall be construed as if "26" were substituted for "39".
(3) Regulations may provide for entitling to disability benefit, subje