"These guys are on death row," Henry told Sydney's The Daily Telegraph newspaper. "There are 10 times as many giant pandas in the world as there are these guys."
The creature - a burrowing, bear-like marsupial that grows up to 88 pounds - is on the brink of extinction. Common wombats are not endangered.
But the newspaper reports of Henry's holiday prompted an outcry by opposition politicians who believe the current economic situation makes it a bad time for a wildlife vacation.
"I think we all love the hairy-nosed wombat," opposition leader Brendan Nelson told reporters. But he said he was "very concerned" that Henry will be out of telephone contact while Australia is going through "one of the most challenging economic periods that we have seen in recent history."
Nelson asked who would advise the government ahead of upcoming decisions on greenhouse gas emissions, tax reform and foreign investment, and noted that oil prices are reaching record highs and inflation is on the rise.
But the government rallied behind Henry. Prime Minister Kevin Rudd told Melbourne radio 3AW that Henry had not taken a break since the new government was elected in November last year and was entitled to decide when he takes vacations.
Henry himself made no apologies for the volunteer "caretaking" work he and his wife will be doing in Queensland state's Epping Forest with the 115-strong wombat colony.
"This place doesn't stop when I am not here," Henry told the Telegraph newspaper, adding that everyone is "entitled to have balanced lives."
Henry was not immediately available for comment Friday.
