Launched in March, the office is led by commissioner Al Aynsley-Green, who is charged with promoting children's rights and encouraging their involvement in the democratic process.
The commissioner's office was set up in response to the inquiry into the death of eight-year-old Victoria Climbie. The inquiry, chaired by Lord Laming, concluded that radical change was needed to safeguard children, and prompted the Children's Act 2004.
The head of communications and participation will report directly to the commissioner and build a communications team after his or her appointment.
Geronimo is providing interim press office support and is devising a comms strategy.
'The commissioner is meeting with organisations that work for children and young people, and children and young people themselves, to determine what his policies should be,' said Geronimo senior account executive Anna Martin.
The commissioner will take into account the United Nations Convention on the Rights of the Child, and promote the involvement of young people in decisions that affect them.