Brown and Obama lead last-minute climate change talks

Prime Minister Gordon Brown and US president Barack Obama were among world leaders engaged in frantic negotiations today, amid chaotic scenes as the deadline for a new climate change deal loomed.

Around 30 countries, including key players China, European states and developing countries, were attempting to resolve issues still standing in the way of securing agreement on tackling global warming.

Mr Brown was among leaders who expressed optimism last night that a deal could be done at the UN talks in Copenhagen after the US backing of a 100 billion US dollar-a-year finance package to help poor countries appeared to have broken the deadlock.

Positive moves were also seen from China on the issue of transparency over the actions the Asian superpower would take to curb its growth in greenhouse gas emissions.

But talks by ministers through the night yielded little progress, leaving officials frustrated as the negotiations remained mired in wrangling.

Almost 120 leaders are at the last scheduled day of the Copenhagen talks, which it had been hoped would result in a political accord that can be turned into a legal treaty within the next year.

There were suggestions at the UN climate summit in the Danish capital that Mr Obama might announce an increase in the level of emissions cuts the US could make by 2020 to seal the deal.

But EU leaders are yet to decide if they are prepared to up their offer of cutting emissions by 20% on 1990 levels by the end of the next decade to a higher 30%, which they have made conditional on securing sufficiently ambitious pledges by other countries.

After more than two-and-a-half hours of talks, an hour's break was called while a new text of a political agreement was drawn up for discussion.

The unscheduled and lengthy negotiations have forced organisers to rip up the timetable for the formal proceedings in public, which have only just got under way three hours late.

Blame for continued deadlock was placed by some attendees, including French president Nicolas Sarkozy, on Chinese resistance to formal monitoring.

Addressing the high-level conference, Chinese premier Wen Jiabao insisted his country took the issue of climate change very seriously and has made, and would continue to make, "unremitting efforts to tackle this challenge".

He said that its target to curb greenhouse gas growth - to reduce the amount of emissions per unit of GDP by 40% to 45% by 2020 - came without any conditions attached and the Chinese would honour it.

And he said: "We remain fully committed to achieving and even exceeding the target."

He added China would increase the transparency of the actions it was taking to curb its emissions growth.