National Party leader Simon Bridges says Winston Peters should focus on governing rather than pursuing his "personal vendettas" by suing senior bureaucrats and National MPs in the courts.
Yesterday Peters lodged fresh legal action in the High Court over the leak of his superannuation payments in 2017.
Those named were State Services Commissioner Peter Hughes, Ministry of Social Development head Brendon Boyle, the Attorney General on behalf of the Ministry of Social Development and former ministers Paula Bennett and Anne Tolley.
Peters is claiming about $450,000 in damages for alleged breach of privacy.
The legal action comes as Peters prepares to take over as Acting Prime Minister for six weeks while Prime Minister Jacinda Ardern is on maternity leave.