The Resident Doctors Association is defending its voting practices from criticism by district health boards, which are trying to prevent a new strike.
The union intends to strike for 48 hours starting at 7am on Wednesday, November 23, following a 48-hour walk-out last month over rosters and pay.
The 20 DHBs' bid for an injunction to stop the strike will be heard in the Employment Court at Wellington next Thursday.
The union's national secretary, Deborah Powell, tonight rejected the DHBs' concern over its inclusion of medical students in its strike ballot.
"These are the graduating doctors - trainee interns - who have been employed under this multi-employer collective agreement.