15.—(1) Paragraph (2) applies where any amount of the recoverable sum notified to the manufacturer or supplier under regulation 17 is not paid in accordance with that notice and so is overdue.
(2) Where this paragraph applies, the manufacturer or supplier is liable to pay to the Secretary of State interest, calculated in accordance with paragraph (3) read with regulation 1(4) and 17(5), on the amount of the recoverable sum which is overdue until that sum is paid.
(3) The interest payable under paragraph (2) shall be simple interest calculated from day to day at a rate of 2.5 per cent per annum over the Bank of England base rate as it may be from time to time applied to any amount outstanding on that day.
(4) For the purpose of this regulation the “Bank of England base rate” means—
(a)the rate announced from time to time by the Monetary Policy Committee of the Bank of England as the official dealing rate, being the rate at which the Bank is willing to enter into transactions for providing short term liquidity in the money markets; or
(b)where an order under section 19 of the Bank of England Act 1998 (reserve powers) is in force, any equivalent rate determined by the Treasury under that section.