Canada has slipped out of the top 10 countries listed in the annual United Nation's human development index — a far cry from the 1990s when it held the first place for most of the decade.
The 2013 report, which reviews a country's performance in health, education and income, places Canada in 11th place versus 10th last year.
A closer look at the trends shows Canada actually did better than last year, but other countries such as Japan and Australia improved at a greater rate.
When the numbers are adjusted for gender inequality, Canada slumps to 18th place. The United States fares even worse -- sinking from third to 42nd place.
"I think it's really sad to see that we've dropped so far under the Conservatives," said deputy NDP leader Megan Leslie.
"And I think it reinforces what the NDP has been saying, but also what organizations like the Conference Board of Canada have been saying, about the fact that there's a growing income inequality gap in Canada.
"That gap creates serious problems, and I don't think the Conservatives have been taking it seriously."
The Prime Minister's Office did not respond to a request for comment on the rankings.
Southern nations on the rise
The main finding of the report, entitled "The Rise of the South," is a positive one on a global scale. It says that countries that had previously struggled with poverty and inequality are now on a steady developmental climb.
It says Brazil, China and India's combined gross domestic product is now about equal to the combined GDP of Canada, France, Germany, Italy, the United Kingdom and the United States.
"When dozens of countries and billions of people move up the development ladder, as they are doing today, it has a direct impact on wealth creation and broader human progress in all countries and regions of the world," says the report.
Even the countries at the bottom of the development list, Niger and the Democratic Republic of Congo, are among those who showed the greatest improvement.
Canada drops out of top 10 most developed countries list