 as a perquisite of an office or employment with that person a sum equal to -  (a) if no interest is payable on the preferential loan or loans, the amount of interest which would have been payable in that year if interest had been payable on the loan or loans at the specified rate, or (b) if interest is paid or payable at a preferential rate or rates, the difference between the aggregate amount of interest paid or payable in that year and the amount of interest which would have been payable in that year if interest had been payable on the loan or loans at the specified rate, and the individual or, in the case of an individual whose [00]>spouse<[00][00]>spouse or civil partner<[00] is chargeable to tax for the year of assessment in accordance with section 0000, the spouse of the individual shall be charged to tax accordingly