OPPOSITION Leader Isobel Redmond's "inane" comments about cutting the public sector has set back serious debate, a leading economist has warned.

Prescott Securities chief economist Darryl Gobbett said there had been substantial growth in the public service and the Government needed to review whether it was affordable and was delivering efficient services.

However, he warned, Ms Redmond's comments weren't helpful to the necessary debate about the need to reform South Australia's economic strategy.

"If we don't get this right as a state, we face a further downgrade on the credit rating and higher taxes, which is then going to lead to a further loss of jobs and businesses in this state," Mr Gobbett told The Advertiser yesterday.

He said the State Government was being forced to keep taxes high to fund the current large public service and tying up money that could be used to fund tax cuts or more job-growing infrastructure.

Ms Redmond's leadership has been under intense pressure since she said last week that the public sector should be reduced by about 20,000 full-time jobs to a total near 65,000. She later said the figure was used in error.

"The way Isobel went on about it, she probably hasn't destroyed the possibility of having a proper debate, but she's put it back," Mr Gobbett said.

"That's an inane way to actually get this debate going."

Martin Hamilton-Smith's prospects of replacing Ms Redmond as leader suffered a blow yesterday with the re-emergence of comments made in March that many of the 20,000 full-time jobs added under the current government were from programs that were "never needed".

Mr Hamilton-Smith told Parliament on March 27: "There are over 18,000 additional public servants, hired year after year.

"It was around 66,900 in 2001-02 and it is well above 85,000 now. We have created all these schemes and all these projects, many of which, arguably, we never needed and which employ all these people."

Ms Redmond is under pressure to stand aside as Liberals fear her statements will cost them key seats in 2014.

One senior Liberal said there was confusion about who was best to replace the current leader.

"I think that some time in the next couple of weeks she will announce that she is going to stand aside," the source said.

"If she is still there in two weeks I will be surprised."

Originally published as Inane slip 'a set back for state'