At the end of his 51 -day "march and fast" initiative for jailed PKR de facto leader Anwar Ibrahim to be freed, disabled activist Isaiah Jacob has issued a warning to Prime Minister Najib Abdul Razak.

Speaking outside the Pasar Seni complex in Kuala Lumpur, the final stop on his journey, Isaiah warned Najib that it will not be the end of the road for his struggle to free Anwar.

"I am warning, or I am setting a condition for Najib, our prime minister, if he is as he says, ‘anak jantan’ (a man).

"I challenge him, if he is really 'jantan', face this OKU...," said the PKR Batu member in his speech, alluding to Najib's swipe at Anwar in his opening speech at the Umno General Assembly on Thursday...