(1)Provision may be made by regulations so that where—
(a)an earner, in respect of any one or more employments of his, is treated by regulations under section 2(2)(b) of this Act as being self-employed; and
(b)in any tax year he has earnings from any such employment (one or more) which fall within section 7(4)(b)(i), but is not liable for a higher weekly rate of Class 2 contributions by virtue of regulations under that subsection ; and
(c)the total of those earnings exceeds £1,600,
he is to be liable, in respect of those earnings, to pay a Class 4 contribution of an amount equal to 8 per cent, of so much of the total as exceeds £1,600 and does not exceed £3,600.
(2)It shall be for the Department, and not the Inland Revenue, to recover Class 4 contributions payable by virtue of regulations under this section and generally to be responsible for the relevant administration; and regulations may in relation to contributions so payable—
(a)apply any of the provisions of Schedule 1 to this Act (except a provision conferring power to make regulations) ; and
(b)make any such provision as may be made by regulations under that Schedule, except paragraph 5.