Ashimbayev elected Kazakhstan's Senate speaker in reshuffle.
It was not immediately clear whether Ashimbayev’s promotion marked any diminution in the power and influence of Nazarbayev and his family in the former Soviet republic, where political decision-making is often shrouded in secrecy.
The powers of parliament are quite limited in Kazakhstan, which has a presidential system of government.
Dauren Abayev, previously minister of information and social accord, has replaced Ashimbayev as the president’s first deputy chief of staff, Tokayev’s office said.
President Kassym-Jomart Tokayev’s deputy chief of staff became speaker of Kazakhstan’s upper house, the Senate, a key position that means he is first in line to take over the presidency if the incumbent resigns or dies.
Maulen Ashimbayev, 49, a political strategist who has held several senior positions in the oil-rich Central Asian nation, replaces Dariga Nazarbayeva, the eldest daughter of Kazakhstan’s powerful 79-year-old former president, Nursultan Nazarbayev.
Tokayev’s office announced Dariga Nazarbayeva’s surprise departure on Saturday but gave no reason. Her father, who steered Kazakhstan to independence after the fall of the Soviet Union in 1991, retains sweeping powers as head of the Security Council and leader of the ruling Nur Otan party.