Newhouse co-founded the National Justice Project in 2016 with Dan Mori and Duncan Fine. As the principal solicitor of the Project his work involves using the law in ways that support and advance social justice and human rights in Australia. It does this by supporting those who are least able to access justice and whose cases can advance human rights within Australia and the Pacific region. In addition the National Justice Project has taken on a number of research, education, advocacy and reform projects such as the Aboriginal Health Project.