Mr Harawira said in a press release issued earlier today that he had put out the "very strongly worded" email to colleagues last week and he stood by that criticism.
"My concern was that time, and design effort had obviously gone into the cannabis law reform promotion, while I hadn't seen the same level of promotion for one of Internet Mana's main campaign themes, Feed the Kids."
The Feed the Kids bill would establish a government-funded breakfast and lunch programme in all decile 1-4 schools.
"I'm very pleased that Internet Party leader Laila Harre independently came to the same conclusion as me and also asked for the campaign not to proceed," Mr Harawira said.
Both Mr Harawira and the Internet Party leader Laila Harre have denied tension over cannabis law reform.
The Internet Party wants decriminalisation of personal use, but Mr Harawira told TV3's The Nation that he did not personally support decriminalisation.
He could not be reached for comment today, but previously told the Herald that his party had reached a consensus with the Internet Party that natural cannabis use should be managed as a health issue, not a crime issue.
However, the starting point for Mana was that cannabis was a harmful drug, along with alcohol and cigarettes, he said.
Ms Harre told the Herald that the party's marketing team had proposed the online campaign, and it required the sign-off of both her and Mr Harawira.
"Quite separately and independently we both instructed that that not go ahead...this was a normal process."
She strongly refuted the suggestion that Mr Harawira's email showed there was tension around the issue of cannabis law reform.
"Quite the opposite. What it shows is how we can work together on our common ground as two parties.
"In this particular case, we have a large amount of common ground. We agree on the medicalisation of marijuana, we agree that there should be a comprehensive review of our drug laws.
"And we agree that cannabis would be better managed as a health issue than as a criminal justice issue."
Ms Harre said the Internet Party had proposed more specific detail on the issue, but there was "enormous common ground".
Read more: Fast Fire on Cannabis: Who's for legalisation?