Where a registered dealer fails to make payment of tax as referred to in clause (a) of sub-section (1) of section 118 in the prescribed manner and by the prescribed date he shall pay a simple interest at the rate as specified in section 34B for the period commencing on the date immediately following the prescribed date for payment of tax and ending on the date prior to the date of payment of such tax or upto the date of commencement of proceedings under section 55, whichever is earlier, upon so much of the amount of tax payable by him according to such return as remains unpaid.