(1)The maximum rate at which a person or persons may be entitled to working tax credit is to be determined in the prescribed manner.
(2)The prescribed manner of determination must involve the inclusion of an element which is to be included in the case of all persons entitled to working tax credit.
(3)The prescribed manner of determination must also involve the inclusion of an element in respect of the person, or either or both of the persons, engaged in qualifying remunerative work—
(a)having a physical or mental disability which puts him at a disadvantage in getting a job, and
(b)satisfying such other conditions as may be prescribed.
(4)The element specified in subsection (2) is to be known as the basic element of working tax credit and the element specified in subsection (3) is to be known as the disability element of working tax credit.
(5)The prescribed manner of determination may involve the inclusion of such other elements as may be prescribed.
(6)The other elements may (in particular) include—
(a)an element in respect of the person, or either of the persons or the two of them taken together, being engaged in qualifying remunerative work to an extent prescribed for the purposes of this paragraph,
(b)an element in respect of the persons being the members of a married couple or an unmarried couple,
(c)an element in respect of the person not being a member of a married couple or an unmarried couple but being responsible for a child or qualifying young person,
(d)an element in respect of the person, or either or both of the persons, being severely disabled, and
(e)an element in respect of the person, or either or both of the persons, being over a prescribed age, satisfying prescribed conditions and having been engaged in qualifying remunerative work for not longer than a prescribed period.
(7)A person has a physical or mental disability which puts him at a disadvantage in getting a job, or is severely disabled, for the purposes of this section only if—
(a)he satisfies prescribed conditions, or
(b)prescribed conditions exist in relation to him.