It's understood some councillors didn't like that either because they thought Foster would be too busy with his mayoral duties.
Foster was unable to announce portfolios at the council's inauguration last week because conversations around who's getting what had taken "a little bit too long", he said.
After more than a week later the conversation has been settled.
Rush has ended up with an Associate Urban Development role and will lead Infrastructure (Three Waters).
In Rush's candidate statement on The Wellington Party's website he said he is completing a Masters in Climate Change Science and Policy, and he is an energy and infrastructure lawyer, now focusing on low carbon energy.
Greenpeace campaigner Steve Abel said Rush did not make it clear what his position was on the campaign.
"I think many people could have read his statement and thought he was a believer in climate science, the mainstream view of it, but he apparently is not from statements he's made quite recently.
"He is much better described as a climate denialist in so far as he denies the severity that is occurring with climate change and he denies the scientific consensus on just how grave the problem is."
But Rush has hit back in a statement, saying he has never denied man-made climate change exists and that the climate change debate had worryingly become binary.
"I do believe the actions we take have an impact and I have argued for the uptake of low carbon energy technology as being the future."
He said anyone who didn't hold the Greenpeace view was labelled a "denialist crackpot".
"I will continue to study climate change and form opinions based on what I learn and put my energies into serving Wellington City and helping it get its mojo back, which is what I was elected to do."
Rush would not comment on whether he stood by the following comments he's made on LinkedIn over the past three months.
In response to an opinion piece titled "Why Greta Thunberg triggers the troglodytes among us" Rush said what was missing from the momentum was science.
"There is a debate between scientists- do you overcook the messaging and lose credibility when predicted catastrophe does not eventuate? Or do you take an honest approach that is scientifically defensible and risk being unable to capture public momentum. Personally, I'm for the latter. Climate Change is manageable. But the extreme narrative that has taken hold works against implementing sensible long-term policy."
In another comment on the same article he said Thunberg's "concerns about the future weather are interesting but not worthy of consideration in the context of proper scientific evaluation".
In a different thread he says there is no "emergency" and he's found uncertainty around the true effect of enhanced levels of CO2, low confidence that tipping points will arise this century and New Zealand was unlikely to distinguish between anthropogenic climate changes from its own highly variable weather.
