Environment ministers must "get their act together" to put international talks to tackle climate change back on track and deal with unresolved issues, Ed Miliband said today.
Speaking in Copenhagen, the Climate Change Secretary urged delegates to make progress before national leaders arrive later this week.
He said: "We need to collectively get our act together and move on and find ways in which we can solve the difficult issues, because these issues that I've mentioned can't all be left to leaders.
"It may be the case that some final issues remain when leaders arrive.
"I've always said the leaders' role in this process is incredibly important to get the final pieces of the jigsaw in place. But what we cannot do is leave a whole slew of issues to leaders.
"I think that the very clear message for negotiators and ministers is we need to get our act together and take action to resolve some of the outstanding issues that we face."
Pacific island Tuvalu has asked for the target to limit global warming to 2C to be brought down to 1.5C.
Mr Miliband said the request should be heeded but the existing plan was "deliverable".
He went on: "The presence of countries like Tuvalu who face immediate and growing threats to their very existence is a salutary reminder of the urgency of this crisis. I think we should go for the most ambition that we should get.
"The truth is, as a result of the emissions already in the atmosphere we are likely to see warming of 1.4 degrees.
"That's why we have taken the position because we think it is a deliverable position to limit warming to no more than two degrees."
A key issue facing those at the meeting is whether they are willing to deliver on the commitments made.
Mr Miliband said: "There are two outstanding issues that I think all countries face, frankly, in this, which is whether we are willing to stand behind our commitments and say that we're going to do what we promise and, secondly, the precise system of monitoring, reporting and verification to make sure people actually follow through on what they promise."
He was joined by International Development Secretary Douglas Alexander, who said the fight against global warming was tied to the battle against poverty.
Mr Alexander said: "The challenge of tackling dangerous climate change and tackling extreme global poverty are now indivisible. For the developing world, climate change is not a future threat, but a contemporary crisis."
Mr Miliband said ministers needed to show more willingness in the talks and understand the urgency of the situation.
He said: "We're now getting close to midnight in this negotiation and we need to act like it.
"That means more urgency to solve problems, not just identify them, more willingness to shift from entrenched positions and more ambitious commitments."
And he warned: "We're not yet on track for the kind of deal we need. This is the critical opportunity. Britain is working in formal and informal settings as persuaders for the ambitious and comprehensive agreement we want.
"If we want to do a deal, we will all need to create greater momentum and make active efforts to find solutions. We need more progress before the leaders arrive."
Mr Miliband attended a meeting of about 40 ministers yesterday ahead of this week's ministerial-level talks at the conference in the Danish capital.
Environment Secretary Hilary Benn has been in Copenhagen to urge negotiators to secure a deal that would protect the world's forests, in the wake of the Prime Minister's call for 25 billion dollars (£15 billion) in funding from rich countries up to 2015 to reduce deforestation, which accounts for almost a fifth of total global emissions.
Mr Alexander is in Denmark for meetings with his counterparts as part of efforts to get a deal which is fair to developing countries that have done least to cause the problem of global warming but are set to be hit hardest.
Former prime minister Tony Blair has urged nations to secure a deal, saying that even if it is not all that everybody wants, there should be and could be an agreement.
Mr Blair said: "We should take the most ambitious level of commitment to cutting emissions, from both developed and developing nations, that is on the table now, accumulate it, make it the basis of the agreement, add to it in ways that we know can make a difference within the next 10 or 15 years, especially in areas like deforestation, and get moving.
"The truth is, such an accord would itself set the world on a new path to a low-carbon future."