Australia Post has named Woolworths supply chain boss Paul Graham as its new chief executive, five months after Christine Holgate quit over a luxury watch expenses scandal.

Mr Graham has worked in digital marketing and retail across Australia, Europe and Asia for 40 years, including as a senior executive at Deutsche Post DHL.

“Paul has a demonstrated track record of delivering results in large, complex organisations and is a proven leader managing large teams,” Australia Post chairman Lucio Di Bartolomeo said on Monday.

Mr Graham will start the role in September.

His annual salary has been set at $1.46 million, with the potential to double his pay through bonuses.

The announcement comes on the eve of a Senate inquiry into Australia Post, with Ms Holgate and Mr Di Bartolomeo both due to give evidence.

Labor communications spokeswoman Michelle Rowland said the inquiry-eve timing of the announcement showed the prime minister and communications minister had “lost their collective marbles”.

“Why was an appointment announced in panic today when the incoming CEO won’t be commencing until September 2021?” she told AAP.

“For the timing to be so blatantly provocative is not only disrespectful to the incoming CEO Mr Graham but shows Scott Morrison remains entirely consumed by short-term political management.”

In an excoriating statement, One Nation leader Pauline Hanson said the timing was an unmistakeable contempt of the process.

“The announcement of a new Australia Post chief executive and managing director today shows absolute arrogance on behalf of the prime minister and two of his most senior ministers,” Senator Hanson said.

“Scott Morrison is attempting to deliberately destabilise witnesses ahead of tomorrow’s Senate inquiry.”

-AAP