The state MP for Kalgoorlie says the behaviour of anti-vax campaigners demonstrating at primary schools is "disgusting".
Ali Kent said trucks bearing signs saying things like "vaccines are not safe" have been circling schools in Kalgoorlie Boulder.
"Why would you needlessly scare children like this?" she said.
Ms Kent said the campaigners were attempting to enter school car parks and arriving during drop-off and pick-up.
"We've thankfully stopped them going into the car parks of schools, because that's trespassing, but they are still going past the lollipop ladies when they know that children are crossing," the Labor MLA said.
Ms Kent said parents had told her the campaigners were causing stress and anxiety among young children.
She said she had been in contact with the police and the education department over the matter.
The WA Lower House representative said she had tried to reason with anti-vax groups.
"Unfortunately, it does fall on deaf ears — they believe what they believe no matter what I say to them and what health information that that I can provide to them," Ms Kent said.
She said people were entitled to their views, but stirring anxiety among children was wrong.
"They are ignoring that advice and that's entirely their decision," she said.
"But when children are needlessly being upset about this, I think it's just a horrible thing.
