Mexico has become the latest country invited to join the Trans-Pacific Trade Partnership talks, which would mark a major blow to Canada's bid for expanded ties with Asia should Ottawa be left out of the deal.
Prime Minister Stephen Harper has been lobbying hard to get Canada at the table, but at this point it hasn't happened.
On Monday, however, Mexico was issued an invitation to join, a move it heartily welcomed.
"Apparently Canada doesn't make the grade, at least not for now," remarked Lawrence Herman, a trade lawyer at Cassels Brock in Toronto.
"If this is true, it's a slap in the face for the Harper government and a real setback for its trade policy agenda."
In Los Cabos, Mexico, where he is attending the G20 Summit, Prime Minister Stephen Harper responded that "First of all, obviously growth is everybody's focus. It should be everybody's focus. That's what we really need. That's obviously part of the solution.
"We need to see some global growth and particularly in those areas where there are challenges we need to see growth. And an important part of our agenda for growth is an ambitious trade agenda. You know, we're delighted that Americans and others have indicated an interest in seeing Canada join the Trans Pacific Partnership and I think for now I'll just leave it at that."
Canada's bid to join has been undermined by the high tariff wall that shields dairy and poultry producers.
One issue reportedly keeping Canada on the sidelines is the reluctance of TPP countries to give new members full veto rights over chapters in the agreement, according to Inside U.S. Trade. The trade publication said Canada is either "unable or unwilling" to meet this demand, which would essentially give the deal's original nine members greater rights.
The current TPP members are the U.S., Australia, New Zealand, Singapore, Chile, Peru, Vietnam, Singapore, Malaysia and Brunei.
Mr. Harper has repeatedly touted the TPP as a key element of the government's aggressive push to expand trade with fast-growing Asia.
There have also been signs of dissent among TPP members about how far and how fast to go in breaking down trade barriers. And that's played against the addition of new members.
U.S. steel makers urged TPP members to also invite Canada to the table.
"We hope that Canada will also be invited to join the negotiations very soon," Thomas Gibson, president of the American Iron and Steel Institute said in a statement. "Having both countries' participation in these important trade negotiations will strengthen the already close relationship we have with our neighbours and will enhance the North American steel industry's international competitiveness."
Pittsburgh-based United States Steel Corp. owns mills in Hamilton, Ont., and Nanticoke, Ont., after taking over Stelco Inc. in 2007. The other major former Canadian steel makers, Dofasco Inc., Algoma Steel Inc. and Ipsco Inc. are owned by European or Asia-based steel makers.