Australia Post has issued a warning to licensees about displaying political material following an incident in Queensland.
A Gold Coast postal agency allowed state Liberal National Party MP Rob Molhoek, who represents the seat of Southport, to display a corflute just inside the doorway but visible through the glass frontage.
Molhoek is up for re-election this Saturday in the state poll.
Communications Minister Paul Fletcher, who was unaware of the incident until it was put to him in parliament on Oct. 26 by Labor MP Milton Dick, said it raised an important issue.
"I understand Australia Post has spoken to the licenced post office licensee in relation to this matter and is reminding all its LPO licensees about impartiality and not displaying political material in outlets," Fletcher told AAP.
An Australia Post spokesman told AAP the materials had now been removed from the outlet.
"While we acknowledge that our employees and other representatives are entitled to their individual views, as a government business enterprise Australia Post needs to ensure its post offices and other facilities are not used for making statements on political issues," the spokesman said.
Senior Australia Post executives are set to front a Senate inquiry next month to answer questions about lavish corporate spending.
Labor is demanding chairman Lucio Di Bartolomeo face parliament to explain why almost $20,000 was spent on luxury watches for senior managers.
Chief executive Christine Holgate has stood aside while a one-month investigation takes place.
Labor is also concerned the board of the government-owned business is stacked with people with strong Liberal connections.
But Fletcher said Labor governments had previously appointed people connected with the ALP.