Former prime minister Najib Abdul Razak says it's his duty to defend the policies of his administration. <br /><br />This come after former minister Nazri Abdul Aziz asked Najib to move to the back seat and let his successor Ahmad Zahid Hamidi drive Umno forward.<br /><br />The Padang Rengas MP said the former premier should emulate Dr Mahathir Mohamad, who stepped aside after Abdullah Ahmad Badawi succeeded him in 2003.