Last week, ministers from five core WTO members - the United States, the EU, Brazil, India and Australia - failed for the second time in just over a week to make progress on agriculture, the most politically sensitive area of the WTO's Doha Round.
"One of the difficulties is, as all countries know, if you put too much on the table too early, you can be asked to put more on the table," said Don McKinnon, secretary-general of the Commonwealth, which principally groups former British colonies.
The 53 members of the Commonwealth make up about a third of the 148 members of the World Trade Organisation. Agricultural subsidies in industrial countries amount to $350 billion per year - or almost $1 billion each day, the Commonwealth estimates.
"WTO issues seem to be dominated by one-minute-to-midnight decisions, and let's hope that they don't forget that," McKinnon told Reuters in an interview.
"But a lot will hold back until the very, very end, when it's too late to put up - you might say - domestic objections to what you're putting forward."
After the United States put forward proposals to contain its huge farm subsidies, pressure has mounted for the European Union to match the offer by opening its lucrative market to imports.
But key EU farm producers, led by France, have angrily accused EU Trade Commissioner Peter Mandelson of already giving away too much and are resisting any further concessions.
The EU says it needs to see parallel progress in other areas of the round such as industrial goods and services.
McKinnon, who was visiting Malaysia en route to a meeting of Pacific Island nations in Papua New Guinea, said Commonwealth members wanted to see significant progress on agriculture in the current round of trade talks.