The NSW Government delivered on its election commitment to address attacks on farming families, such as those carried out by Aussie Farms, by announcing on-the-spot fines for activists who invade private properties and jeopardise their biosecurity.

Monday's declaration was part of a broader suite of measures being considered by the government to protect Upper Hunter farmers' right to farm.

"Today the Minster for Agriculture and the Deputy Premier have taken an important step in stopping on-farm trespass by vegan vigilantes by imposing on-the-spot $1000 fines for trespass," Mr Johnsen said.

"Biosecurity is key to the ongoing viability of NSW agriculture and is extremely important to farmers.

"Now if an activist takes it upon themselves to invade someone's property, which is in violation of their biosecurity plan, then they will be guilty of an offence.

"Not only will it be a $1000 fine, but courts will have the ability to impose further fines of $220,000 or even $440,000 if a corporation is to blame.

"Activists who want to cause trouble for farmers in Upper Hunter are on notice - this is step one.

"We are looking at even more penalties to protect farmers who produce the food and fibre we need to ensure that not only are we fed and clothed as individuals, but that NSW can thrive economically."

Mr Johnsen said the farmers needed some piece of mind.

"My constituents have had enough and so has the NSW Government," he stated.

"If anyone has welfare concerns, report them to the appropriate authority like the RSPCA."

Under the changes to the Biosecurity Regulation 2017 it will become mandatory for site visitors to comply with a Biosecurity Management Plan.

Anyone who enters a designated biosecurity area without permission and without complying with the plan's requirements may be guilty of an offence under the Biosecurity Act 2015, and subject to the new, harsher penalties.

The penalties will come into effect from August 1.

Authorised officers such as NSW Police will be able to issue $1000 on-the-spot fines.

Further penalties will be available to courts, including $220,000 for individuals and $440,000 for corporates.

To access the new offence, farmers will need to have a biosecurity plan in place and appropriate signage.

Farmers are encouraged to contact the Department of Primary Industries or their Local Land Services office for more information.

Go to www.dpi.nsw.gov.au/biosecurityact