Four months out from the NSW election, former Labor prime minister Paul Keating has given a ringing endorsement of the Liberal Premier Mike Baird's performance and taken a swipe at the opposition.

Mr Keating and the Premier attended the official naming of the Barangaroo Point headland park in Sydney, when the former prime minister was asked how he thought Mr Baird was doing in the top job.

"I think very well," Mr Keating said.

"I think exceptionally well... there's only one reward in public life and that's public progress and the test of the relevance of leaders is can they get the job done?

"Can the state and the country be better? And I think in this case we are seeing a lot of positive changes."

Mr Baird has recently stepped up his sales pitch to sell off 49 per cent of the state's poles and wires, by unveiling a $20 billion infrastructure plan that outlines how he would spend the proceeds.

Keating warns against opposing infrastructure plan

The state Labor opposition is against the sell off, but Mr Keating said he supported Mr Baird's position.

"I support the Premier's view about this," Mr Keating said.

"There are still some obscurantists in the Labor party... there's still some there."

Mr Keating cautioned Opposition Leader John Robertson, who has led the push against the sell off, about his position.

"My advice to him is to adopt the policies that are most productive to the state," he said.

He avoided questions about whether he thought Mr Robertson was the wrong man for the job.

Mr Keating once famously said that if Mr Robertson became Labor leader the party would have no future.

Just after NSW Labor lost government in a landslide in 2011, he told the ABC's 730 Report: "If Robertson were to be elected leader, he would have no moral vantage point to lead from.

"If you've actually connived in the destruction of the parliamentary leader and are a principal cause why 24 or 25 members of Parliament have lost their seats, if those dead men and women are hanging around your neck - and they are - you've lost the vantage of the leadership.

"You've lost the point of moral authority."

Asked about his earlier remarks, Mr Keating today said: "I said that in the interim before he got the leadership, now he's the leader I can't say things quite as frankly as that."