"Nuclear power? Yes please." Can this really be the attitude the Government would adopt should Labour be re-elected Thursday week? Yesterday's headlines suggested that after the election there would be a green light to a new generation of nuclear power stations to help combat global warming.

"Nuclear power? Yes please." Can this really be the attitude the Government would adopt should Labour be re-elected Thursday week? Yesterday's headlines suggested that after the election there would be a green light to a new generation of nuclear power stations to help combat global warming.

I'd be very surprised if Tony Blair went down this route as I believe him to be thoroughly committed to renewable energy resources. In his foreword to Labour's White Paper two years ago entitled "Our Energy Future - Creating a Low Carbon Economy", he said, "As we move to a new low carbon economy there are major opportunities for our businesses to become world leaders in technologies we will need for the future - such as fuel cells, offshore wind and tidal power."

There is a powerful campaign now gathering momentum suggesting that Britain will only achieve its climate change targets with a revival of nuclear power, but this is misguided. Nuclear is neither necessary nor desirable for this purpose, and would entail economic, military and environmental risks that should be avoided.

Britain is one of only two countries in the EU - the other being Germany - which is set to meet its climate change targets. Indeed we are likely to achieve those targets by a healthier margin than probably any other country in the industrialised world.

Who needs nuclear when its downsides of nuclear are so stark? First, nuclear is far more expensive. The Government's Performance and Innovation Unit estimated electricity generating costs from onshore wind at 1.5p-2.5p per kilowatt hour by 2020, from offshore wind at 2p-3p, and from gas at 2p-2.3p. But generating costs from nuclear power were put at 2.5p-4p per kilowatt hour, half as expensive again as gas and up to twice as expensive as wind. In a competitive capitalist economy that is the killer point.

Next, there is the problem of nuclear waste, the safe long-term storage of which no country has yet solved. And we have an enormous amount of it. Even if there were no new nuclear build, which was the agreed position in the 2003 White Paper, the DTI has admitted that the 10,000 tons of high and intermediate level nuclear waste currently stored mostly at Sellafield would increase to half a million tons by the end of this century - a 50-fold increase. When this waste stream contains some of the most toxic materials known to man and no one knows what to do with it, does it make sense deliberately to add to the pile? Against this background, the argument of the nuclear lobby that we already have such a massive amount of this dangerous waste so that adding a bit more to it wouldn't make much difference is frankly contemptible.

Third, after 9/11 the security of vulnerable installations has now become a key issue. Is it really sensible to build more nuclear stations which are an obvious target for terrorist attack, or to increase the transportation of nuclear materials by land or sea at risk of hijack?

If, then, for very good reasons a nuclear future is rejected, where are we to find our energy? How do we fill the gap as the Magnox and the advanced gas-cooled reactors currently responsible for some 23 per cent of electricity generation are steadily phased out in the next two decades? What is the potential for development of renewables - wind-power, biomass, wave power or tidal barrages, and ultimately solar power? At present, we have the worst of all worlds. The renewables contribution to electricity generation is still tiny at about 3 per cent. The Government made a clear declaration two years ago to push strongly down the renewables route, but has done far too little to deliver on the scale required. Yet the potential for wind-power in Britain is recognised to be far ahead of both Germany and Spain, the EU's leading markets and, on a global basis, above Texas, the previously strongest market.

It is not that renewables have failed or are not up to the job. It is rather that they have never been seriously tried. Despite attractive pricing under the Renewable Obligation Certificates system, far too little has been done to deal with the principal barriers to expansion - planning blockages, aviation issues, grid network constraints, and grossly inadequate funding, all of which were correctly identified by the White Paper.

Three new initiatives are urgently needed to keep Britain's strong record on climate change firmly headed in the right direction. One is the promotion of a global policy of Contraction and Convergence in carbon emissions between developed and developing countries as the only fair and equitable way to get countries like China and India on board, so that a global problem is met by a truly global response.

Second, the enormous in-built subsidies still granted to the fossil fuel industries should be steadily phased out and the savings transferred into a massive expansion of renewables. And third, the prodigious waste of energy by both industry and domestic households should be addressed by much, much stronger incentives to maximise energy efficiency.

If Labour is really to be a leader on the environment, these are the third-term tests we will have to pass.

Michael Meacher, the Labour candidate for Oldham West and Royton, was Environment spokesman from 1997 to 2003