• Abbott under water as Sinodinos steps aside
• PM throws fuel onto red tape bonfire

Federal Labor has demanded Prime Minister Tony Abbott explain why he changed his position on Arthur Sinodinos after initially standing by the assistant treasurer.

Senator Sinodinos on Wednesday stood aside from the ministry over a NSW anti-corruption inquiry, saying he did not want his involvement as a witness to distract “from the important work of the government”.

Earlier this week, Mr Abbott defended his frontbencher before accepting his decision as the “right and decent thing” to do.

Manager of opposition business Tony Burke raised questions about what Senator Sinodinos had told the prime minister to “completely changed his view from where he’d been two days earlier”.

He said Mr Abbott should say what explanation was given to him that was not given to the parliament.

Mr Burke argued something must have “radically” changed.

“Arthur Sinodinos chose not to tell the Senate what (it) was that had changed (but) he certainly told the prime minister,” Mr Burke told Sky News on Thursday.

“The prime minister took a completely different view yesterday to what he’d taken the day before, and I think the public is entitled to know why.”

Unanswered questions

Shadow Treasurer Chris Bowen said Mr Abbott had failed to answer questions in parliament about his knowledge of the Independent Commission Against Corruption (ICAC) inquiry in Sydney.

The commission has heard the Liberal powerbroker and former chief of staff to John Howard was paid $200,000 for 100 hours work a year at Australian Water Holdings.

AWH took him on as a board member and later chairman to “open doors” to Liberal politicians, ICAC was told.

“It’s simply a matter of accountability and transparency in being honest to the parliament about the questions being asked, and therefore honest with the Australian people,” Mr Bowen told ABC Radio.

“The prime minister obviously doesn’t want to talk about this issue, doesn’t want to reveal what he knew and when he knew it.”

Sinodinos denials

Senator Sinodinos has denied any wrong doing and is expected to appear at ICAC as a witness at a later date.

Parliamentary secretary Josh Frydenberg urged the media not to play judge and jury over Senator Sinodinos.

He said he has full confidence that Senator Sinodinos will be fully vindicated.

Mr Frydenberg said he’d spoken to the senator and passed on his support following his decision to step aside.

“I think we should be very careful not to sully his reputation any further,” he told ABC TV on Thursday.

Colleagues supportive

The man filling in as assistant treasurer, Finance Minister Mathias Cormann, said Senator Sinodinos had not been accused of any wrongdoing by ICAC and was co-operating as a witness.

Senator Cormann praised his Liberal colleague as “a fine man” and a “man of the highest integrity”.

“Arthur Sinodinos is a very decent man and we’re confident that he’ll be vindicated and that he’ll return to his position in the ministry,” he told ABC radio.

Shadow Treasurer Chris Bowen said Senator Sinodinos’s departure will be a blow for budget preparations.

Treasurers heavily rely on their assistants for a lot of the detailed work, Mr Bowen said.

“This … will not help budget preparation which I understand is already behind the eight ball,” Mr Bowen told reporters in Canberra.

Mr Bowen said the government was running late on its expenditure review process.

But Education Minister Christopher Pyne said Treasurer Joe Hockey and the expenditure review committee had everything under control.

“They’re doing an excellent job in preparing for a difficult budget,” Mr Pyne said.

AAP