Former New South Wales premier Bob Carr has lashed out at the “debauched ethos of mateship” that has plagued politicians on both sides of the political divide in NSW.

He was speaking after the resignation of NSW Premier  Barry O’Farrell in the wake of controversy over his appearance at the Independent Commission Against Corruption.

Mr Carr, the last NSW premier to serve a full term, said that ICAC, which was established by former NSW premier Nick Greiner with his backing, had “imposed a standard that NSW politics has struggled to keep up with”. Greiner himself was the subject of an unfavourable finding at ICAC, although he later had this overturned in the courts.

Mr Carr, who was foreign minister in the latter period of the Gillard/Rudd Government, lashed out at the culture of NSW politics, telling Sky News: “It is a debauched ethos of mateship and factional solidarity linked to fundraising.”

Mr O’Farrell was caught out by ICAC over receiving a $3000 bottle of Penfold’s Grange from then-Australian Water Holdings (AWH) boss Nick Di Girolamo in 2011.

The letter that has cost Barry O’Farrell his job.

What I do know is if I had received a bottle of 1959 Penfolds Grange I would have known about it and I did not receive a bottle of Penfolds Grange.

The premier had said he “never received” the wine while under oath at the commission, but the ICAC has revealed a hand-written thank-you note signed by Mr O’Farrell for the wine.

He maintained he spoke truthfully at the commission and said the receipt of the wine was a “significant memory fail”.

“I still can’t remember the receipt of the gift of 1959 Grange; I can’t explain what happened to the wine, but I do accept there is a thank-you note signed by me and as someone who believes in accountability, I accept the consequences.”

Mr O’Farrell had denied receiving the wine at all, saying he spent Easter 2011 on the Gold Coast, and even Oscar the cocker spaniel was away from the O’Farrell family home on Sydney’s north shore about the time the delivery is said to have been made.

The gift was never declared on the premier’s pecuniary interests register although MPs must disclose any gift worth $500 or more.

But Mr Di Girolamo had told the inquiry he received a thank-you call from the premier after sending the wine.

On Tuesday afternoon, Mr O’Farrell was shown a record of a 28-second telephone call from his mobile number to Mr Di Girolamo, made about 9.30pm on April 20, 2011.

“I’ve no knowledge – I don’t know about this phone call,” Mr O’Farrell told the commission.

“What I do know is if I had received a bottle of 1959 Penfolds Grange I would have known about it and I did not receive a bottle of Penfolds Grange.”

Prime Minister Tony Abbott praised Mr O’Farrell for falling on his sword.

“I have enormous respect and admiration for Barry O’Farrell,” he said. “I have known him for two decades and he is a friend of mine. He innocently, inadvertently misled ICAC yesterday and he has taken the utterly honourable decision.”

Today is an insight into how the Liberal Party operates in NSW. They have allowed donors and lobbyists to get involved in the public administration of this state.

Mr O’Farrell is the second NSW premier to fall at the hands of ICAC. Mr Greiner resigned in 1992 after being found to have acted corruptly over the Terry Metherell affair.

The Liberal party will now have to elect a new leader with speculation mounting over two possible candidates including Treasurer Mike Baird.

NSW Opposition Leader John Robertson said the shock resignation proved the Liberal Party let lobbyists into the heart of government.

“What we see today is not about a bottle of wine,” he said. “Today is an insight into how the Liberal Party operates in NSW. They have allowed donors and lobbyists to get involved in the public administration of this state.”

Public confidence in the state’s politicians had been “rocked to the core” by the premier’s actions in what was a “very sad day for the people of NSW”, Mr Robertson said.

Asked if he would follow Mr O’Farrell’s lead if his failure to report a $3 million bribe from Michael McGurk in the sale of union property Currawong was found to be inadequate, Mr Robertson said they were “very different matters”.

“We are talking about a government before ICAC – not some kangaroo court that’s been set up in the Legislative Council,” he said.