Last Friday, a petition was launched by the National Muslim Youth League, which wants the production of the film They are us to be shut down.
On Wednesday morning, the collection had over 70,000 signatures.
The terrorist attack was aimed at a mosque and several of the victims of the attack and New Zealand Muslims are strongly critical of the fact that the film will instead be mainly about Prime Minister Jacinda Ardern.
Mayors do not want to let in film crews
"The film revolves around white people and will therefore continue with 'white-washing' of the terrible violence against Muslims," it says in the name collection.
Christchurch Mayor Lianne Dalziel is also deeply critical of the planned film and says that she does not know where it will be shot, but that the film teams "are not welcome" to the city, writes the New Zealand herald.
"Very sensitive"
The Prime Minister herself has spoken and said that she was neither involved nor knew that the American film was in the making.
"It is very early and very sensitive for New Zealand," she said in a statement.
One of the victims' families has written a letter to the actress Rose Byrne, intending to play Arden in the film, and asking her to say no to the role.
On Monday, New Zealand producer Philippa Campbell withdrew from the project.
The film will be written and directed by director Andrew Niccol, also from New Zealand.
51 were killed
Australian right-wing extremist Brenton Tarrant was sentenced in 2020 to the law's most severe punishment in New Zealand: life imprisonment, with no possibility of early release.
51 people were killed and 40 injured when Tarrant opened fire in the al Noor mosque in Christchurch during Friday prayers on March 15, 2019.