The NSW Farmers Association says a new push to ban mulesing in the state would put millions of sheep at risk.
Legislation to ban mulesing in NSW has been introduced into the State Parliament by the Animal Justice Party's Mark Pearson.
Speaking in the NSW Legislative Council, Mr Pearson said if passed the ban wouldn't apply until January 1, 2022.
But chairman of NSW Farmers' animal welfare committee, Jim McDonald, said no viable alternative to surgical mulesing was available yet and most of the state's producers still had a "fair way to go" to breed sheep that didn't need mulesing.
"The association doesn't support this bill in any shape or form," he said.
Mr McDonald, a veterinarian who runs 2500 crossbred sheep on "Eubindal", Binalong, in southern NSW, said the association would be vigorously lobbying politicians and parties not to support the push to outlaw mulesing.
He said making the argument that mulesing caused short-term pain and discomfort was easy but the lifetime flystrike protection it brought to sheep needed to be kept in perspective.
Around 70 per cent of Merino lambs in Australia are still mulesed.
NSW Farmers supports the use of pain relief when mulesing.
Mr Pearson's Private Member's Bill to amend the Prevention of Cruelty to Animals Act 1979 would also mandate pain relief for procedures such as castration, dehorning and tail docking.
He said hundreds of thousands of people in Europe and the US were now watching the mulesing debate.
"The issue here - and this is what this bill tries to address - is that much of the wool that is clipped (shorn) in Australia goes around the world and it goes to very, very high apparel buyers and retailers such as Hugo Boss, Zegna, Abercrombie & Fitch et cetera.
"The world is watching what we are doing in our backyard to animals that provide a fibre that travels through China being washed and spun, through New Zealand being knitted and ends up in a Hugo Boss store in New York as a garment.
"The bill is of its time. Animal welfare is now a mainstream concern. NZ introduced a complete ban on mulesing in 2018," Mr Pearson said.
Meanwhile, both WoolProducers Australia and the VFF are concerned the definition of mulesing will be changed in new Prevention of Cruelty to Animals Regulations due to take effect in Victoria on December 14.
Feedback on the regulations which include the mandatory use of pain relief for mulesing closed last Thursday.
WoolProducers and the VFF want Victoria to stick with the current national definition which describes mulesing as the removal of skin from the breech and/or tail of a sheep with mulesing shears.
The Victorian draft regulation makes no reference to mulesing shears which means any type of alternative to surgical mulesing that removes skin such as the use of chemicals, laser technology, clips or some other new process or treatment down the track would require pain relief.
VFF Livestock Group president, Leonard Vallance, said after lengthy consultations he was confident Victoria would stick with the current national definition of mulesing.
WoolProducers chief executive officer, Jo Hall, said the proposed definition change would also have serious implications for the National Wool Declaration for non-mulesed wool which was based on the current national definition of mulesing.
Australian Wool Innovation invested $31.2 million in breech flystrike research from 2001-17 seeking alternatives to surgical mulesing - none of which have yet emerged as a real alternative - which under Victoria's new definition would be classified as mulesing.
"Hopefully they (Victorian Government) will come to their senses," Ms Hall said.
Besides mandatory pain relief for mulesing the new draft Victorian animal welfare regulations would require some form of insulation on metal ute trays and trailers when carrying dogs in temperatures above 28C.
As well, owners of sheep would not be allowed their fleece to a length greater than twice the average annual growth for the breed or more than 250mm (whichever is shorter).