Scoobydooby's calculations are based upon a fallacy. There is no requirement, per se, for a company to employ its part-time employees on the same basis as full-time ones. Every employee's contract is entirely separate from that of any other employee. A company is (except as is explained in the next paragraph) free to pay it's full time staff �1000 per hour and give them 9 months holiday while paying its part-timers �5.52 per hour and giving them the minimum statutory holidays.
In some companies, however, the proportion of female part-timers is far higher (or lower) than the proportion of female full-timers. In such circumstances, a company must treat part-timers and full-timers alike, otherwise they would be guilty of indirect (and unlawful) sexual discrimination. Other companies have no such obligation upon them.
Assuming that the company is not forced to treat part-timers and full-timers alike, under the provisions of the previous paragraph (and that there are no collective bargaining agreements relating to this), the part-timer's only legal entitlement is to receive 19.2 (= 4.8 x 4) paid mornings of holiday per year (including any days when the business is closed). As long as this requirement is met, the employer has met the statutory obligations.
Chris