A disparate group ranging from church leaders to farmers have taken their concerns about proposed anti-protest laws to the steps of WA's Parliament.

A group of about 100 people gathered on the steps to hear speaker after speaker condemn the State Government's proposed laws as an attack on fundamental civil rights.

One of the key groups opposing the laws are farmers involved in the Lock the Gate campaign to prevent fracking gas exploration on their land.

Dongara mango and rockmelon farmer Rod Copeland, who farms about 370 kilometres north of Perth, said he feared the proposed changes would criminalise his right to protest.

"It's impinging on my rights to protect my family, my business and the general community and I want to see it stopped," he said.

Government has insisted the legislation would only target radical protesters using devices like chains or thumb locks to block or stop lawful activities.

But opponents raised concerns that proposed laws did not specify devices, but instead referred to a "thing" which may be used to prevent lawful activity.

They also say the law change would reverse the onus of proof, requiring the person suspected of intending to use protest to prevent a lawful activity, to prove in court they had no intention to do so.

Mr Copeland said that left farmers open to criminal charges.

"I have a piece of chain and a padlock under the seat of my ute that I use for my trailer, and if I go to a protest I can be arrested and even end up in jail because it's perceived that I will use it," Mr Copeland said.

Nationals leader Terry Redman addressed the protest rally and assured the groups that only radical protests would be affected.

He was presented with a petition with more than 14,000 signatures opposing the laws.

But he was jeered as he told the rally that the Nationals were supporting the Bill.