§ Mr. Austin Mitchellasked the Secretary of State for Social Services what is his estimate of the net cost of a change in the structure of national insurance contribution for (a) employers and (b) employees so that (i) the contributions began at £1,800 and £3,600 for single persons and married couples, respectively, (ii) contributions were limited to 9 per cent. of the amount in excess of these figures up to a maximum of £1,260, (iii) those not contracted out would pay in addition a sum of 2.15 per cent. of total earnings as at present and (iv) the reduced rate allowances were abolished.