* Lamy to present packed Doha work plan to Pittsburgh G20
* WTO can take stock of progress in December
* Unclear whether Doha deal in 2010 will be possible
By Jonathan Lynn
GENEVA, Sept 22 (Reuters) - It is uncertain whether trading powers will make the political effort needed over the rest of this year to complete a new global trade deal in 2010, the head of the World Trade Organisation said on Tuesday.
Briefing the group's 153 members on his message to this week's G20 summit in Pittsburgh, WTO Director-General Pascal Lamy refrained from his usual comments that a deal in the long-running Doha round can be reached.
"At this stage I remain cautious in my forecast. It would be premature for me to predict today that the necessary political engagement will in fact take place over the next three months," he said in a speech to WTO members.
Lamy said a deal in the Doha round, now nearly 8 years old, would be possible only if members translated the calls of leaders and ministers for agreement into action through hard bargaining on the few remaining issues.
Trading countries should be able to take a view in December on whether a deal can in fact be done next year after an intense round of negotiations between now and mid-December on all the areas in the talks, he said.
The packed schedule is the outcome of a week of talks among negotiators in Geneva reinforced by senior officials from state capitals, after key trade ministers made yet another call to conclude Doha when they met in New Delhi earlier this month.
Lamy said he would present this to the Pittsburgh summit with the message that leaders should call on their negotiators in Geneva to make the deal happen. "They now have the road mapped out, but they still have to walk it," he said.
"Leadership is about responsibility. Failure to act -- not just in Pittsburgh, but more particularly here in Geneva -- will be hard felt by the entire international community at this time of economic crisis," he said.
The Doha round was launched in late 2001 to boost the world economy and help developing countries prosper by removing more trade barriers.
It has missed repeated deadlines as exporters and importers and rich and poor countries fight over cutting farm subsidies and industrial and agricultural tariffs.
Many negotiators in Geneva, where the WTO is hosting the main trade talks, are expressing frustration or resignation that key trading powers are unwilling to show the flexibility to turn the pledges by the G20 and other groups into action.
A frequently heard complaint is that the United States is unwilling or unable to move, as President Barack Obama has more pressing priorities, from healthcare to the financial crisis. That criticism is unlikely to come into the open at Pittsburgh.
"No one's going to beat up on Obama when he's the host," said one diplomat from a rich country. "The moment of truth will come later," he said, pointing to the December stock-taking identified by Lamy. (Editing by Stephanie Nebehay and Tim Pearce)