EU downplays chance of climate alliance with China

"We will work very closely with the Chinese, as with a lot of other key parties," Ms Hedegaard told journalists in Brussels before heading to Mexico this weekend.

"I have seen some press reports asking why doesn't the EU and China ally themselves and then everything will fall into place," she added. "I'm not sure its that easy. There are many parties that we have to co-operate with."

The Danish politician stressed the need for give-and-take between developed and emerging economies on the range of difficult issues up for discussion.

"To us it really means a lot whether we get progress in the field of transparency," she said, reiterating European calls for a system to measure, report and verify (MRV) national emission cutting efforts. Wealthy countries have made this a central demand of their poorer counterparts before committing to aid transfers.

A number of analysts have called for closer EU-China co-operation in recent weeks however, including Chatham House energy research director, Bernice Lee.

"With the collapse of climate legislation in the US, it is up to the EU and China as the world's largest markets for low-carbon goods and services to strengthen their role as the locomotive of the low-carbon economy," he wrote in a paper last month.

Environmental groups also agree a Sino-EU alliance would have advantages. "The biggest emitters - China and the US - are the biggest players," WWF climate activist Jason Anderson told this website. "The key question at the moment is how to bring pressure on the US."

Despite the recent US mid-term elections ushering in a wave of climate change sceptics on Capitol Hill, together with the White House's failure to enact cap-and-trade legislation this year, Ms Hedegaard said she remained optimistic.

"It shouldn't be an obstacle in itself," she said.

As part of the EU's 'balanced' package, European negotiators will push this week for non-binding emission pledges made last December by various countries to be 'anchored' in the UN process.

Brussels also wants an agreement on transparency rules (MRV), reform and expansion of carbon market mechanisms, as well as a mechanism to reduce tropical deforestation.