''Yes, it's quite an unusual step for us. We usually write letters and tend to work a little more behind the scenes,'' branch president Elaine Armstrong said.

''But coal seam gas mining is a major concern for our members. It will adversely affect our future food supplies, we'll see good farming land go out of production and pressure from gas companies wanting access to farms is also adding to the stress and complications of farming.''

Mrs Armstrong said the CWA had hoped the NSW government would heed calls from rural communities for a moratorium on coal seam gas exploration.

''That didn't happen, so we feel the government hasn't fulfilled what was expected of them. They have broken promises,'' she said.

The CWA is one of eight groups actively supporting an anti-fracking rally to be held outside the Parliament of NSW in Sydney on May 1 that will see protesters bused in from across the state. Taking a stand on coal seam gas mining puts the normally apolitical women's voluntary group - Australia's biggest at 44,000 members - in radical company.

Organised by NSW Farmers to highlight rural concerns over food security and groundwater pollution, the ''Protect Our Land and Water'' rally is also supported by social media activist group GetUp and rural anti-fracking campaign alliance Lock the Gate.

Yesterday morning, the CWA posted a link to the rally on its Facebook page, suggesting members ''make the effort to be there''.

A regional co-ordinator with Lock the Gate in north-west NSW, Carmel Flint, has watched the grassroots anti-fracking alliance grow to more than 80 member groups across the state in recent months. ''Rural women, especially farmers' wives, are the backbone of our membership. They are driving this campaign because they can see the impact that coal seam gas mining of farmland will have on the future of their families,'' she said.

Queensland cotton farmer Ruth Armstrong is one of the new faces of rural radical green politics. An honours ecology graduate, she runs a grain and cotton farm with her husband David on the Darling Downs. She will speak tonight at a public forum in Canberra on the environmental and financial impacts of coal seam gas mining on farmers. ''The mining companies claim they only need an area of land about half the size of a netball court for the average well-head. That doesn't factor in the land needed for roads, right of way and pipelines. There is no way we could continue to run our farm as a productive enterprise if we allowed mining on our property.''

Ruth Armstrong will speak at a public forum tonight at the Pilgrim Conference Centre, Northbourne Ave, at 6pm.