As arguably the biggest beneficiary of the deal covering 40% of the global economy, Vietnam was expected to be among the first to ratify the TPP, the prospect of which helped spur record foreign investment last year in its booming manufacturing sector.

"The TPP will not be on the assembly's agenda because the government's proposal is not completed," a parliament source familiar with the matter told Reuters. He did not elaborate.

Vietnamese ratification was widely considered a formality, having already been approved in January by the top brass of the ruling Communist Party.

The National Assembly is 96% composed of party members and domestic opposition to the TPP is unheard of. Its next session begins on Oct 20.

The delay means that at the earliest, ratification by Vietnam would be several months after the Nov 8 US presidential election.

Obama's trade policy has come under heavy domestic scrutiny during the US campaign, with Democrat Hillary Clinton expressing reservations about the TPP and Republican Donald Trump firmly opposed. Ratification of the pact by US legislators is by no means certain.

Negotiations were completed last year for the TPP, dubbed a "mega-regional accord", to create a trading zone of 12 members with a combined gross domestic product (GDP) of $27 trillion.

It seeks to raise standards and challenge China's economic influence. But debate in the United States has caused jitters among some TPP members, which include Japan, Malaysia, Singapore, Brunei, Peru, Chile, Australia, New Zealand, Canada and Mexico.

Obama has expressed confidence of winning congressional approval for the TPP before he leaves office, warning that failure to do so would undermine US leadership in the region and allow China to set the rules of regional commerce.

With Vietnam's strengths in electronics, textiles, seafood and commodities, the TPP is seen as a game-changer for its export-dominated economy, and a means of boosting US influence in China's backyard.

Reuters - September 16, 2016