Several Nationals MPs have broken ranks with the New South Wales Government to vote against controversial legislation to ban greyhound racing, but it has passed Parliament regardless.

Key points: Three National Party MPs voted against bill to ban greyhound racing

Three National Party MPs voted against bill to ban greyhound racing Bill approved by Lower House after earlier passing Upper House

Bill approved by Lower House after earlier passing Upper House Ban on racing to take effect from July, 2017

The bill, to stop racing in the state from July 1, was approved in the Lower House of Parliament, despite misgivings from a number of conservative MPs.

National Party MPs Chris Gulaptis, Kevin Humphries and Katrina Hodgkinson all crossed the floor to vote with Labor to oppose the bill.

"And as difficult as that is, to vote against the Government ... and to sit with the Opposition ... unfortunately there is no halfway for me in this debate and I choose to be with my constituents 100 per cent," Mr Gulaptis said.

Ms Hodgkinson said people in her Cootamundra electorate were angry, depressed and hurt about the decision to close the greyhound racing industry.

"When people have something involuntarily taken from them, when it's their passion and the reason for getting out of bed in the morning, it is natural for them to get upset or depressed or both, and wonder what's the point of it all," she said.

"These people are not criminals and they deeply resent the way in which the advertising campaign that has been funded by the Government implies that they are being cruel to their beloved animals."

Another Liberal MP, Kevin Conolly, said he did not think the bill was the right response and he would instead abstain from voting.

"I cannot stand by and see all of these people tarred with the same brush because some in their industry have done the wrong thing," he said.

"I believe that this response is the wrong one. I would have chosen to reform the industry rather than close it."

Nationals MP Andrew Fraser also abstained from the vote.

Greyhounds 'killed in the most violent of ways'

Earlier, Liberal MP Ray Williams, whose grandfather and uncle had been greyhound trainers, told Parliament it gave him no pleasure seeing the demise of the racing code, but there were important reasons for it.

"As a lad riding horses around my own area … growing up, it was not uncommon to find many mounds of destroyed greyhounds in the bush, killed in the most violent of ways, by bashing their heads in with a hammer, and then dumping them en-masse in the bush," he said.

Opposition racing spokesman Michael Daley said the opposition to the ban within the Government reflected badly on Premier Mike Baird.

"Thousands of people will wake up this morning and learn they have no future," he said.

"This will be a devastating impact for thousands of families across New South Wales who rely on the greyhound industry to pay their bills and mortgages and feed their families."

The ban, from July 1 next year, was proposed following revelations of live baiting and a report from a special commission of inquiry.

Mass graves containing racing greyhounds were also discovered.

Mr Baird told Parliament that with responsibility came criticism.

"Some claim that this decision has been taken hastily and without consultation but the very opposite is true," he said.

"When the shocking Four Corners story on this emerged more than a year ago our response was not to make any knee-jerk decisions. Rather, it was to undertake the most detailed inquiry ever conducted into greyhound racing in Australia, led by a former High Court judge.

"We have a responsibility to make decisions for the people of New South Wales that are based on the facts, however difficult they may be."

Ban will lead to more dead dogs, Foley warns

Opposition Leader Luke Foley said the ban would lead to the deaths of thousands of healthy greyhounds in NSW.

"If the Government gets away with this, with legislation to outlaw and criminalise a sport, an industry, a way of life in this country, they can do it to any of you," Mr Foley said.

"It will have a devastating effect on thousands of decent and law-abiding citizens in this state," he said.

Ms Hodgkinson said she could not support a decision which she believed would result in the loss of thousands of full-time and part-time jobs in NSW.

"I take this tough decision today not to vote with Labor, but I have to oppose this legislation on behalf of my electorate, on behalf of those who are sick and depressed by this proposed ban and who feel they have no voice," she said.