The Trade and Merchandise Marks Act,1958
Section 31. Registration to be prima facie evidence of validity
(1) In all legal proceedings relating to a trade mark registered under this Act (including applications under Sec. 56), the original registration of the trade mark and of all subsequent assignments and transmissions of the trade mark shall be prima facie evidence of the validity thereof.
(2) In all legal proceedings as aforesaid a trade mark registered in Part A of the register not be held to be invalid on the ground that it was not a registrable trade mark under Sec. 9 except upon evidence of distinctiveness and that such evidence was not submitted to the Registrar before registration, in all legal proceedings as aforesaid, if it is proved that the trade mark had been so used by the registered proprietor or his predecessor-in-title as to have become distinctive at the date of registration.