The Liberal MP who replaced Christopher Pyne at the last federal election accidentally slugged South Australian taxpayers hundreds of dollars he spent on Uber Eats during his time as a political adviser — before paying the money back.

Key points: James Stevens had to pay back more than $300 of taxpayer funds he spent on Uber Eats orders in late 2017

James Stevens had to pay back more than $300 of taxpayer funds he spent on Uber Eats orders in late 2017 The revelation was included in documents released following a Freedom of Information request

The revelation was included in documents released following a Freedom of Information request It comes amidst a row over taxpayer-funded spending on political advertising

Documents show James Stevens inadvertently billed taxpayers over $300 for about a dozen orders he placed with the food delivery service in late 2017, when he was a staffer for then-opposition leader, now Premier, Steven Marshall.

Mr Stevens stepped down as Mr Marshall's chief of staff earlier this year to seek Liberal preselection for the seat of Sturt, following Mr Pyne's retirement, and was elected to Federal Parliament in May.

The documents listed about a dozen transactions with Uber Eats "made in error". ( Reuters: Neil Hall )

The revelation about the bungle comes amidst an intensifying row over expenses, with the SA Government forced to defend its political spending during its time in opposition after earlier criticising Labor over its use of taxpayer funds.

Treasurer Rob Lucas said the fact that Mr Stevens had charged taxpayers for food deliveries was an "accident" and that the transactions "were all repaid".

"When he went overseas, they made adjustment to the Government-issued card to allow the use of the credit card for Uber travel whilst in the United States," Mr Lucas said.

"Evidently, when he came back to Australia and was eating copious amounts of Uber Eats-provided nutritious food, he didn't realised that Uber Eats was connected to the Uber travel app.

"As soon as he became aware of that, he repaid all of that money way back in early 2018. It was an error and it was repaid. The taxpayers can feel comfortable they haven't been dudded.

"They can rest assured that Mr Stevens was well-fed with Uber Eats."

Liberals downplay spending in opposition

The Uber Eats transactions were listed in documents outlining Liberal taxpayer-funded spending during the party's time in opposition from 2016 to 2018.

The documents were published online late on Friday following a Freedom of Information request by Labor.

Mr Stevens has been contacted for comment.

SA Treasurer Rob Lucas accused Labor of misusing taxpayer funds. ( ABC Radio Adelaide: Malcolm Sutton )

Earlier this week, Mr Lucas accused the Opposition of misusing $11,000 worth of taxpayer funds on ads that aired on commercial radio last month.

He said the money was allocated to the office of Opposition Leader Peter Malinauskas, and was not meant to be used for party political purposes.

"No leader of the opposition in the past, Labor or Liberal to be fair, has ever, in my view, been brazen enough or silly enough to actually use the taxpayer funding in this particular way," Mr Lucas said on Monday.

"You can't have a situation where the taxpayers of South Australia are paying for political advertising which is being authorised by the state secretary for the Labor Party."

But the same documents which reveal Mr Stevens's mistake also show that, during their time in opposition, the SA Liberals spent more than $8,000 of taxpayer funds on Facebook advertisements and paid more than $10,000 to political campaigning software company NationBuilder.

"Opposition is all about holding Government to account, and we are doing it and they did it," Labor MP Susan Close said.

"What's stunningly hypocritical is the way that they slam us at the beginning of the week and admit at the end of the week that they were doing it themselves."

However, Mr Lucas said the Liberal spending was "comprehensively different".

"No-one has ever said that members of Parliament or indeed leaders of the opposition cannot advertise or take political positions," he said.

"Members of Parliament, leaders of the opposition, have the capacity to put out leaflets, write letters, to email, to use social media to criticise the Government of the day."