Both of Wollongong's iconic lighthouses have been graffitied with the words Climate Justice Now painted on them in red.
The vandalism happened ahead of today's student climate change rally in Wollongong.
State member for Wollongong, Paul Scully is disappointed by the vandalism and has told Wave FM he warned protesters to keep their noses clean.
"When I spoke with the organisers of the climate strike last week I said to them the one thing they can't do is do silly things that will annoy and turn people off their cause.
"I think there is a general level of community support for action on climate change but this sort of silly behaviour turns people off.
"No matter how well intentioned the message might have been, it sours everything and I'd call on the people who did it to get out there with some white paint and clean it up," Scully said.
The Wollongong Rally begins at lunchtime outside the Illawarra Performing Arts Centre on Burelli Street.
Image: 9 News Illawarra