The National MPs Paula Bennett and Anne Tolley are both to appear at the High Court in Auckland on Thursday to defend themselves against claims they breached Winston Peters' privacy.
Mr Peters is suing both MPs, as well as top civil servants and a government department, seeking $450,000 dollars in damages.
It relates to a leak in 2017 to media revealing Mr Peters had been overpaid his pension by nearly $18,000 dollars over seven years and had paid it back.
Meredith Nugent was an area manager for the Ministry of Social Development, when Winston Peters' pension overpayment first came to light.
Yesterday she told court she was the one who made the phone call telling Mr Peters of the error.
The two arranged to meet in person - where Ms Nugent showed Mr Peters his application from 2010.
He had declared he was separated and living apart from his wife but didn't declare he was in a relationship with Jan Trotman.
RNZ deputy political editor Craig McCulloch has been at court this week.
