However, a spokesman for the protest said the six MPs who had their offices doused with fake blood were engaged in "criminal neglect".
Electorate offices of five Labour MPs, including Dunedin MP David Clark, were targeted across the country yesterday.
National MP Michael Woodhouse also had his Dunedin electoral office smeared in red paint.
"I’m confused about what their message is. They’re a bunch of extremists who I don’t think will ever be satisfied ..." Mr Woodhouse said.
Protesters had offered to clean up the paint, but a professional graffiti cleaner advised it would have been difficult to remove after drying.
"I think they might not have been able to reach their own lofty expectations," Mr Woodhouse said.
In a one-line statement, Dr Clark said “everyone has the right to protest, but this kind of vandalism is unacceptable, and frankly alienates people from the important cause of climate action”.
Restore Passenger Rail spokesman James Cockle, of Dunedin, said the politicians targeted were chosen because they were "key players".
"We think the truth is that we can’t afford to not have passenger rail.
"Our message to them is that the blood is on your hands. The action that they’re showing is criminal neglect, and they need to step up," he said.
Save Our Trains campaigner Victor Billot, of Dunedin, said the group agreed the government was not doing enough, but was concerned the action taken by Restore Passenger Rail could be counterproductive.
It was unlikely to have a positive effect on politicians, and it risked confusing and alienating the public.
There were many groups advocating for improved rail services, taking a variety of approaches.
There was a large, building body of public support for passenger rail, including in the South for a rail service from Christchurch to Invercargill.
‘‘Our goal is to build that wide public support we need to get improved passenger rail,’’ Mr Billot said.
A police spokeswoman said officers had received reports of damage to buildings in Great King and Princes Sts, in Dunedin, along with offices in Christchurch, Wellington and Auckland.
"Police are following positive lines of inquiry into the circumstances of the incidents and to locate those involved," the spokeswoman said.
