An action for damages for negligence, other than one to which section 11 of this Act applies, shall not be brought after the expiration of fifteen years from the date (or, if more than one, from the last of the dates) on which there occurred any act or omission—
(a) which is alleged to constitute negligence; and
(b) to which the damage in respect of which damages are claimed is alleged to be attributable (in whole or in part).
This section bars the right of action in a case to which subsection (1) above applies notwithstanding that—
(a) the cause of action has not yet accrued; or
(b) where section 14A of this Act applies to the action, the date which is for the purposes of that section the starting date for reckoning the period mentioned in subsection (4)(b) of that section has not yet occurred;
before the end of the period of limitation prescribed by this section.