Labour Party leader Phil Goff has conceded the party has been damaged by the Darren Hughes affair.
Mr Hughes, 32, the party's chief whip, resigned from Parliament on Friday, just days after it was revelead police were investigating a complaint against him from an 18-year-old man.
Mr Hughes insists he has done nothing wrong and is co-operating with a police inquiry.
The Labour leadership knew about the complaint for two weeks, but took no action, including advising party president Andrew Little or senior MPs, until it became public.
Mr Goff still believes his decisions were correct, saying it is never a good idea to have a trial by media, and he wanted to let police get on with their job.
However, he admits some Labour MPs may have concerns about his handling of the matter.
Mr Goff faces two critical meetings this week as he faces continued scrutiny about his handling of the affair.
Mr Goff will face questions from frontbench MPs at a meeting in Dunedin on Tuesday and is due to attend the party's ruling council meeting in Wellington on Saturday.
If Mr Goff attends the council meeting, he will need allay concerns about his failure to act immediately once he knew that Mr Hughes was under investigation.
Radio New Zealand's political editor reports that many within the party believe Mr Goff put his personal friendship with Mr Hughes ahead of the political interests of Labour.
Few are satisfied with Mr Goff's explanation that he did not act immediately because he did not want to be seen trying to influence the police investigation. However, Mr Goff will first have to convince his senior MPs that he handled it properly.
Mr Goff conceded that better communication was needed, but told Morning Report on Monday that talk of a leadership challenge was just speculation.
Deputy leader Annette King says there is no threat to Mr Goff's leadership and what the party is interested in doing is focusing on what matters to people - the state of the economy and the rising cost of living.
Former party president Mike Williams says it is hard to say whether the complaint involving Mr Hughes will have any bearing on the outcome of the election in November.
However, he believes Mr Goff made an error in judgment by not informing Mr Little and senior MPs of the matter earlier.