The New Zealand First MP was questioned after deciding to stay in the two roles - and continue getting paid for both.
In a statement, Arbuckle originally said he would remain as a councillor until October this year to avoid a "costly" by-election, should he resign before then.
"At the moment, I believe I'm still doing the job of a councillor," he said, video-calling home from Wellington but still making it to most Marlborough District Council meetings in person.
But after "feedback and upon reflection", on Tuesday he said any money he got from his council role since October's election would be "donated to a local district community charity".
Councillors in Marlborough with no extra responsibilities were paid $40,250, but Arbuckle was on the economic finance committee, earning more.
An MP's base salary was $163,961, plus office expenses, superannuation, accommodation supplements and more.
