As respects the year of assessment 1999-2000 and subsequent years of assessment, the Principal Act is hereby amended -

(a) by the substitution of the following for section 461:

"461. Standard rated personal allowances.

(1) In this section -

'appropriate percentage', in relation to a year of assessment, means a percentage equal to the standard rate of tax for that year;

'the specified amount', in relation to an individual for a year of assessment, means -

(a) £8,400, in a case in which the claimant is -

(i) a married person who -

(I) is assessed to tax for the year of assessment in accordance with the provisions of section 1017, or

(II) proves that his or her spouse is not living with him or her but is wholly or mainly maintained by him or her for the year of assessment and that the claimant is not entitled, in computing his or her income for tax purposes for that year, to make any deduction in respect of the sums paid by him or her for the maintenance of his or her spouse,

or

(ii) a widowed person, other than a person to whom subparagraph (i) applies, whose spouse has died in the year of assessment,

and

(b) £4,200 in the case of any other claimant.