21.—(1) Where a responsible body intends to recover a payment (in whole or in part) in accordance with regulation 18(2)(d), the responsible body may also recover (on demand) interest on that amount at the rate in paragraph (2).
(2) The rate is one per cent above the sterling 3 month London interbank offered rate on a day to day basis, from the date of payment of grant until the date of recovery.
(3) In any proceedings for recovery under these Regulations, a certificate issued by the responsible body showing the rate or rates of interest, the amount of such interest recoverable and the period for which interest is calculated shall, unless the contrary is shown, be conclusive of those matters.