Rob Campbell is adamant he hasn't crossed a line in his public criticism of National's Three Waters policy.

The now former chair of Te Whatu Ora has been fired by Health Minister Ayesha Verrall, for breaking Public Service rules about political neutrality.

He told Mike Hosking he doesn't regret what he's said, but does regret he will be losing direct contact with thousands of health workers and their families.  

Campbell contends it's perfectly legitimate under the Code of Conduct for someone not in their official capacity to make political remarks, as long as they don't undermine the public trust in their organisation.

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