4.—(1) In the case of an income-related allowance, the amount payable in respect of a claimant shall be—
(a)if he has no income, the applicable amount;
(b)if he has an income, the amount by which the applicable amount exceeds his income.
(2) Subject to subsection (3), the applicable amount for the purposes of subsection (1) shall be calculated by—
(a)taking such amount, or the aggregate of such amounts, as may be prescribed, and
(b)if in the claimant’s case the conditions of entitlement to the support component or the work-related activity component are satisfied, adding the amount of that component.
(3) Regulations may provide that, in prescribed cases, the applicable amount for the purposes of subsection (1) shall be nil.
(4) The conditions of entitlement to the support component are—
(a)that the assessment phase has ended,
(b)that the claimant has limited capability for work-related activity, and
(c)that such other conditions as may be prescribed are satisfied.
(5) The conditions of entitlement to the work-related activity component are—
(a)that the assessment phase has ended,
(b)that the claimant does not have limited capability for work-related activity, and
(c)that such other conditions as may be prescribed are satisfied.
(6) Regulations may—
(a)prescribe circumstances in which paragraph (a) of subsection (4) or (5) is not to apply;
(b)prescribe circumstances in which entitlement under subsection (4) or (5) is to be backdated;
(c)make provision about the amount of the component under subsection (4) or (5).