"When they stop attacking you and start laughing at you, it's pretty bad," the Liberal minister said.

"On the day when all the Liberals supported him, he refused to rule out leaving the Coalition."

Another senior Liberal minister said:" "A week ago he had his tail between his legs, promising he would never turn on the government again.

"Less than a week alter, he has broken his promise. He never changes his spots."

A furious Mr Barilaro also attacked his Liberal colleague, Planning Minister Rob Stokes, accusing him of leaking against him about over correspondence from a major NSW property developer.

The Herald revealed on Wednesday that concerns raised by developer and former Newcastle mayor Jeff McCloy were the only stakeholder correspondence Mr Stokes received from Mr Barilaro.

Mr McCloy sent his concerns about the planning policy to Mr Barilaro's Monaro electorate office, which was then forwarded to his ministerial office and then on to Mr Stokes' office.

Mr Stokes' office confirmed that it had not received any similar correspondence about an "individual farmer, timber company or peak industry body regarding the Koala SEPP" from Mr Barilaro.

Mr Barilaro's office did not provide a response to written questions about the correspondence, but in parliament the Deputy Premier said Mr McCloy's letter was forwarded by a "lovely" receptionist.

He said passing on the email did not constitute "representation" on behalf of Mr McCloy.

"That is actually my office doing the job because guess what, unfortunately for me, and maybe because I have reputation for delivery people come to my office," Mr Barilaro said.

Labor backbencher and former leader Michael Daley described Mr Barilaro's attack on Mr Stokes as "the most extraordinary breaches of cabinet solidarity I have ever seen".

"Is the Premier going to sack him or he is going to resign from cabinet," Mr Daley said.

NSW Labor leader Jodi McKay told parliament during the no confidence motion: "You cannot threaten the future of the government and not face consequences."

Deputy opposition leader Yasmin Catley said: "Your tantrums will cost the nationals even more at the next election. You are untenable...your leadership is in tatters."

But Deputy Nationals leader Paul Toole said the party was behind Mr Barilaro and described the no-confidence motion as "political nonsense".