12.—(1) The prescribed circumstances for the purposes of section 115(1)(a) of the 1988 Act (obligatory revocation of licence) are that, in the case of the holder of a large goods vehicle driver’s licence who is under the age of 21, the counterpart of his ordinary driving licence bears more than three penalty points.
(2) Where a large goods vehicle driver’s licence is revoked under section 115(1)(a) the cases in which the person whose licence has been revoked must be disqualified indefinitely or for a period, shall be determined by the Secretary of State.
(3) Where the Secretary of State determines that a person whose licence has been revoked under section 115(1)(a) is to be disqualified for a period he shall be disqualified until he reaches 21 years of age or for such longer period as the Secretary of State may determine.