On Sunday Stuff reported seven formal complaints were laid with the party and up to 12 people made general complaints about the staffer.

Labour's ruling council agreed to investigate the claims of bullying and harassment in February and appointed three party members to investigate.

They were, Christchurch-based McLellan, along with lawyer Simon Mitchell and Honey Heemi, of Labour's Māori Council. 

They delivered a report to the council, which recommended no disciplinary action be taken. That recommendation was accepted.

On Thursday when Ardern was asked if it was appropriate for McLellan to hold the interim position, she said it was temporary.

It was an automated process in the constitution that defaulted to the senior VP, she said.

The party's council had the power to appoint an alternative but she had not heard if they would.

"To highlight, this is very temporary - there is only a matter of weeks required to ballot members and then of course a new president will be put in place."

According to the Labour Party constitution, if the position of president becomes vacant before the next Annual Conference, the General Secretary must, within 14 days invite the constituent organisations with voting rights to provide nominations.