Another tough day for former top Civil Servant Rob Campbell.

He's been sacked as the chair of the Environmental Protection Authority today after losing the same title at Te Whatu Ora earlier this week.

The controversy began after Campbell posted on social media, criticising the National Party's Three Waters policy.

Under the Public Service Act, civil servants are required to exercise political neutrality.

Campbell says he'd just be whistling in the dark if he claimed it doesn't hurt a bit.

"I'm losing contact with a lot of things and people that I love very much, so yeah, it hurts but there is some big issues at play here, and you've just got to get on with it."

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