He denounced attempts by some developed nations to junk the Kyoto Protocol on greenhouse gas emissions and said climate change "is becoming the pretext for pursuing protectionist policies under a green label" which would be rejected by India and other developing nations.

In a strongly-worded intervention at the Commonwealth Heads of Government Meet (CHOGM) here, Singh said, "it is unfortunate that the global discourse on climate change has become enmeshed with arguments about maintaining economic competitiveness or level-playing fields."

Singh disapproved of attempts by some developed countries to lower expectations from the December Summit on Climate Change, saying the negotiations should not be pre-empted and effort should be made to achieve as much convergence as possible.

"If the outcome at Copenhagen diminishes rather than enhances the implementation of the UNFCCC (UN Framework Convention on Climate Change) in respect of the specific components of mitigation, adaptation, finance and technology, it would represent a serious setback, no matter how we seek to characterise this result," the Prime Minister told the Summit of 53 former British colonies.

Noting that India has repeatedly emphasised on the need for the Copenhagen outcome to be "comprehensive, balanced and above all, equitable," Singh said it must be comprehensive in the sense that it must cover all the inter-related components of mitigation, adaptation, finance and technology.

"This means we should resist a partial outcome," he said at the Commonwealth meet where climate change is the main theme of discussion.

Singh declared that "India is willing to sign on to an ambitious global target for emissions reductions or limiting temperature increase but this must be accompanied by an equitable burden sharing paradigm."

"We acknowledge the imperative of science but science must not trump equity. Climate Change action based on the perpetuation of poverty will simply not be sustainable," he said at the conference attended by special invitees UN Secretary General Ban Ki-Moon and French President Nicolas Sarkozy besides the leaders of member countries.

Observing that climate change is a challenge of global dimensions which deserves an international and collaborative response, he said, "climate change is becoming the pretext for pursuing protectionist policies under a green label. This would be contrary to the UNFCCC and a violation of the WTO as well. India and other developing countries will strongly resist this."

Singh said that despite efforts of the developing countries, party to the Kyoto Protocol, the second track of multilateral negotiations, no progress has been achieved in fulfilling the mandate of the Working Group on it, which has been meeting for the past three years.

"The attempts by some countries to dispense with the Kyoto Protocol altogether has generated avoidable misgivings and have been strongly resisted by all developing countries without exception," he said, hoping that "a legally valid instrument to which we too are parties, will not be set aside in a cavalier manner" as it will "undermine credibility in any future legally-binding instrument."

The Prime Minister said contrary to impressions which have been "mistakenly circulated," the Kyoto Protocol will not expire in 2012, the year which marks the end of the first commitment period for developed country parties to fulfil their legally binding obligations to reduce their economy-wide emissions by a specific quantified figure.

"The negotiations under way are to review progress achieved in meeting the targets by 2012 and to sign on to more significant obligations in the second commitment period commencing in 2013," he said.

He highlighted that provisions of the UNFCCC had barely been implemented and in the meantime, the threat of climate change had become more compelling than had been envisaged when the Rio Convention was concluded in 1992.

Hence, he said the failure to achieve an outcome on four components of fight against climate change mitigation, adaptation, finance and technology -- at Copenhagen would serve as a setback.