15.—(1) Where the Scottish Ministers intend to recover on demand a grant in whole or in part in accordance with regulation 14, they may, in addition, recover interest on that amount at a rate of 1 per cent above the base lending rate of the Bank of England calculated on a daily basis for the period from the date of payment of the grant until the date of recovery.
(2) In any proceedings for recovery under these Regulations, a certificate issued by the Scottish Ministers showing the rate or rates of interest, the amount of such interest recoverable and the period for which interest is calculated is, unless the contrary is shown, conclusive of those matters.