(1) Where a person to whom pension has become payable (whether or not it has become payable to the person by virtue of section 136) would, but for this section, be entitled to an increase in the rate at which the pension was payable to or in respect of the person immediately before the commencement of a prescribed half - year and:
(a) in a case where the pension is age retirement pension, early retirement pension or invalidity pension--it became payable to the person during the half - year (in this section referred to as the preceding half - year ) immediately preceding the prescribed half - year;
(b) in a case where the pension is spouse's pension:
(i) if, immediately before the death of the person by reason of whose death the spouse's pension became payable, a pension (other than a partial invalidity pension) was not payable to the deceased person--the spouse's pension became payable during the preceding half - year; or
(ii) if, immediately before the death of the person by reason of whose death the spouse's pension became payable, a pension (other than a partial invalidity pension) was payable to the deceased person--the pension that was payable to the deceased person became payable during the preceding half - year; or
(c) in a case where the pension is orphan pension:
(i) if, immediately before the death of the person by reason of whose death the orphan pension became payable, a pension (other than a partial invalidity pension) was not payable to the deceased person--the orphan pension became payable during the preceding half - year;
(ii) if, immediately before the death of the person by reason of whose death the orphan pension became payable, spouse's pension was payable to the deceased person--the spouse's pension became payable during the preceding half - year and pension (other than partial invalidity pension) was not payable to the person in relation to whom the deceased person was a spouse or was not payable for the part of the half - year that spouse's pension was not payable to the deceased person; or
(iii) if, immediately before the death of the person by reason of whose death the orphan pension became payable, a pension (other than a partial invalidity pension or a spouse's pension) was payable to the deceased person--the pension that was payable to the deceased person became payable during the preceding half - year;
the following provisions of this section have effect in relation to that first - mentioned pension.
(2) If:
(a) the pension;
(b) where clause (1)(b)(ii) or (1)(c)(iii) applies--the pension that was payable to the deceased person;
(c) where clause (1)(c)(ii) applies and pension was not payable to the person in relation to whom the deceased person was a spouse--the pension that was payable to the deceased person; or
(d) where clause (1)(c)(ii) applies and pension was payable to the person in relation to whom the deceased person was a spouse--that last - mentioned pension;
became payable after 16 June or 16 December (as the case requires) in the preceding half - year, the person is not entitled to the increase.
(3) If:
(a) the pension;
(b) where clause (1)(b)(ii) or (1)(c)(iii) applies--the pension that was payable to the deceased person;
(c) where clause (1)(c)(ii) applies and pension was not payable to the person in relation to whom the deceased person was a spouse--the pension that was payable to the deceased person; or
(d) where clause (1)(c)(ii) applies and pension was payable to the person in relation to whom the deceased person was a spouse--that last - mentioned pension;
became payable on or before 16 June or 16 December (as the case requires) in the preceding half - year, the amount of the increase is so much only of the amount that but for this section would have been the amount of the increase as bears to that last - mentioned amount the same proportion as the number of months in the period that commenced on the day on which the pension referred to in whichever of paragraphs (a), (b), (c) and (d) is applicable became payable and ended on 30 June or 31 December (as the case requires) in the preceding half - year bears to 6.
(4) If the period referred to in subsection (3) is less than 1 month, that period shall be treated as 1 month.
(5) If the period referred to in subsection (3) consists of a number of whole months and a part of a month:
(a) where the number of days in that part of a month is less than one - half of the number of days in that month--that part of a month shall be disregarded; and
(b) where the number of days in that part of a month is not less than one - half of the number of days in that month--that part of a month shall be treated as a whole month.