"I think the mayor's reasons need to be challenged on this."
Mr Casson listed the links and connections he has throughout the community, calling it a matter of a principal.
"The appointment by the mayor on age is ageism."
Councillor Geoff Taylor said that it was not a debate on age, but a debate about merit.
"I believe that is why Ryan has been nominated for this," Mr Taylor said.
"James if I could offer my own advice, it is that I find Ryan good to engage with and discuss issues.
"I haven't been able to find that sort of ease with you. Talk of age is pure bs."
However, mayor King said the decision was based on age.
"I am choosing on age. Ryan is over a decade younger than anyone on this table, and we've always talked about giving a voice to young people," Mr King said.
Councillor Paula Southgate, who chairs the community and services committee, said she would support the decision made by the mayor, but had sympathy for both councillors Henry and Casson.
"I very much admire Siggi for her level of attendance at community events, she is always there," Ms Southgate said.
"James also, I regularly see him at events as well and I am aware of the amount of efforts he puts into community events."
Councillor Mark Bunting, who lost the job last year, said he wished the discussion was not taking place in the first place.
"We would not be having this discussion if I didn't mess up. This is Phillip's job, so whatever we have got to do it with the same quorum and class that Phillip would have done," Mr Bunting said.
Deputy mayor Martin Gallagher has been the acting deputy chairan since councillor Bunting had it revoked from him for sending an offensive meme to journalist Angela Cuming.
Mr Bunting only held the role for a short time after taking it over following the death of councillor Philip Yeung last year.