Lack of urgency in the Durban meeting halls and pressing issues elsewhere threaten to block progress as the UN climate summit enters its final days.
Some delegates said there was no clear process for bridging divides.
Others suggested that the EU summit would see the leaders "thinking of the euro crisis, not the climate crisis".
US climate envoy Todd Stern's set-piece speech was heckled by a campaigner protesting that the US was blocking a deal here, which Mr Stern denied.
Most nations appear to want a strong deal - but the exceptions are some of the world's most powerful countries.
The US, India, China and Brazil are among those likely to oppose parts of the solution sought by the EU and the majority of developing countries.
As those four together account for nearly half of the world's emissions, the diplomacy is harder than the mere numbers might indicate.
With two days left to run in the South African city, some experienced delegates said the talks appeared to lack urgency.
One minister told BBC News there was no sign yet of a text that would contain the essential top-line elements of a political deal
By this stage in last year's meeting, they said, the Mexican hosts had already decided a process to resolve outstanding differences; but that is not the case here.
Final stages of negotiations often involve a few calls between heads of state, who can sometimes break an impasse when their underlings cannot.
But with EU nations desperately searching for a solution to the eurozone crisis at the Brussels summit, delegates questioned whether European leaders would have the time or inclination to make the key calls.
Coalition of the willing
There is clearly a broad coalition here that wants a process leading to a new, legally-binding agreement covering all nations to begin as soon as possible.
It includes the Least Developed Countries bloc (LDCs), the Alliance of Small Island States (Aosis), the European Union and some countries in Africa and Latin America.
But the big emitters are holding out for a longer timescale.
Brazil has made clear that it does not want the process to begin until 2015 at the earliest, while China, India, and the US are believed to favour even longer timescales.
Part of their argument is that discussions should start after the Intergovernmental Panel on Climate Change (IPCC) has published its next assessment report in 2013-4, so that policy is based on the latest science.
The UN climate convention (UNFCCC) itself is also due to review its existing agreements in 2013-5, to judge whether they need strengthening.
But Brazil, China and India also argue that Western countries should follow through fully on their existing pledges first before any new process starts - including by making further emission cuts under the Kyoto Protocol.
"If you committed to do something, you have to implement what you said you would do," said Luiz Alberto Figueiredo Machado, head of the Brazilian delegation.
The EU is willing to put its existing emission pledges under the Kyoto Protocol, provided that the summit agrees a clear roadmap or process leading to a new global agreement under which, eventually, every nation's emissions could be regulated.
"The EU is not about to agree to a Kyoto Protocol second commitment period without strong commitment on the part of players who would not be a part of that agreement," said UK Climate Secretary Chris Huhne.
Most observers agree that the biggest question is whether China, India, Brazil and the US can be persuaded to move far enough towards the common ground shared by the EU and the LDCs and Aosis.
One view shared by delegates from different blocs is that Brazil will move, China might - but India and the US will be tougher.
"In that case, the question will be whether India or the US or both really want to be the ones to stand up and say 'we broke the deal in Durban'," said one delegate who did not wish to be named.
Forest of issues
Many other issues are on the agenda besides emission cuts.
On the Green Climate Fund - the new body that will eventually collect and disburse sums of $100bn (£64bn) per year to poor countries - there is consensus on rules.
The draft agreement for this meeting specifies that a levy on fuel used by international shipping could be one source of money for the fund.
But progress on agreeing other sources is being blocked, reportedly by the US.
"Negotiators have an option on the table here to raise billions of dollars to help protect poor people on the front lines of the climate crisis by capping emissions from the shipping sector," said David Waskow, Oxfam's policy adviser.
"Blocking progress on this practical solution would undermine a future where everyone has enough to eat."
The meeting is also supposed to implement agreements already reached in principle, including on a scheme to fund Reducing Emissions from Deforestation and forest Degradation (Redd) and the transfer of clean technologies to developing countries.
On forests, there are genuine disagreements over technical and social factors.
But there is also a chance that any or all of these issues could be held hostage as leverage in the bigger picture.
While many delegates say there is still all to play for, there are outliers on both sides.
"Very optimistic" and "a car crash" were two very divergent views of the state of play with two days remaining.
Follow Richard on Twitter