Although he ruled out a direct challenge for the Liberal leadership, the former treasurer did not answer any questions on whether he would accept an overture to accept the leadership if Brendan Nelson quit. Mr Costello had previously indicated to colleagues that he might enter the fray if Malcolm Turnbull launched a challenge against Dr Nelson.

Someone who has made a career out of studying grocery prices and its related issues is Associate Professor Frank Zumbo, of the Australian School of Business at the University of NSW. “What is going on is an insult to the intelligence of Australian consumers,” Zumbo says. “We’ve just had an inquiry into grocery and food prices. The report is a disgrace. It is a whitewash.”

Only weeks ago, Australian Competition and Consumer Commission chairman Graeme Samuel told the ABC’s 7.30 Report that “there would be very few observers in the marketplace that would say to you, ‘Coles and Woolworths are not vigorously competing against each other.”‘ Now, in a somersault worthy of an Olympic gold medal, Samuel has concluded that “the grocery market is workably competitive.”

The GroceryChoice website shows a trolley full of food on Queensland’s Sunshine Coast is worth about $150, while the same groceries in Darwin and Hobart cost about $12 more.

GroceryWatch and its related measures are meant to satisfy the expectation the prime minister built up during the election campaign that Labor would do something to bring down the cost of living. But as in the case of FuelWatch this exercise is more likely than not to come back and bite him on the proverbial.