Countries most vulnerable to climate change have attacked rich nations for rethinking the global emissions treaty timetable

Countries most vulnerable to climate change have attacked rich nations for rethinking the global treaty timetable that would enforce legally binding emissions cut targets.

As delegates engaged in a fifth and final day of UN climate talks in Spain, European nations downplayed expectations for a legal treaty to come out of next month's key climate summit in Copenhagen.

Instead, negotiators were working on a draft political agreement in which rich nations would promise to reduce emissions and to finance aid for helping the world's poorest cope.

Such a deal would carry the authority of world leaders who would sign it in Copenhagen. Nations would agree to stick to their promises while they continue negotiating the details of a treaty, taking as long as another year.

The shift - an implicit admission of defeat after two years of tough UN negotiations - follows acknowledgement that several countries may not be politically ready to sign a legal pact by next month. "After Copenhagen, talking action must turn into taking action," said Yvo De Boer, the UN official who is leading the talks.

The head of the Indian delegation, Shyam Saran, said the key to success at Copenhagen would be "the willingness of (industrial nations) to come up with significant reduction targets," and that a consensus by all 192 nations would still be binding. "We don't share the view that it is no longer possible. If it were no longer possible, we would rather pack up and go home," he said.

Oxfam also it was "essential" that a deal in some form be done in Copenhagen.

Some delegates warned, however, that a watered-down deal could face trouble at Copenhagen. "The Africans do not intend to say 'yes' to a weak deal," said Greenpeace. "Failure is still an option on the table."

A bloc of 43 island nations urged leaders of the world's industrial nations to double efforts toward concluding an ambitious and legally binding pact during at the December 7-18 climate summit.

The islands, along with the world's least developed countries, are demanding steep emissions cut pledges by the developed world that some scientists say would limit global warming to at most 1.5C above pre-industrial temperatures. Industrial nations have been aiming for targets that limit global warming to 2C above.