(1) The Principal Act is hereby amended by the substitution for Part I (inserted by section 14 of the Act of 1990) and Part III (inserted by section 4 of the Act of 1990) of the Fourth Schedule thereto of the Parts set out in Schedule B to this Act.
(2) This section shall come into operation -
(a) in so far as it relates to unemployment assistance, on the 24th day of July, 1991,
(b) in so far as it relates to pre-retirement allowance, deserted wife's allowance, prisoner's wife's allowance, single woman's allowance, lone parent's allowance (other than lone parent's allowance payable in respect of a widow or widower) and carer's allowance, on the 25th day of July, 1991,
(c) in so far as it relates to old age pension, blind pension, widow's (non-contributory) pension, lone parent's allowance payable in respect of a widow or widower and orphan's (non-contributory) pension, on the 26th day of July, 1991, and
(d) in so far as it relates to supplementary welfare allowance, on the 29th da