BBC Radio 4's Today programme asked an expert on either side of the argument for their views.

Professor David Wallace, vice-president of the Royal Society

It's not a question of wanting more power stations built, but under the current regime, the government is rightly planning to phase out the existing nuclear power stations.

And this means that a key current component of our capacity for energy generation is being phased out.

The big question is what is going to replace it?

My answer would be a partial replacement (with more power stations) is probably needed to make up the shortfall.

The reason is our concern that targets for replacing the current nuclear capacity by fewer renewables - that is wind and similar - require a massive investment.

One of the key technological issues with renewables is the variability of supply Prof David Wallace Royal Society

We are concerned that investment will not be made in the time and will leave us with a shortfall which will have to be made up by carbon.

And one of the things we do share with Greenpeace is a concern that we need to cut down the consumption of oil and gas.

Investing in renewables is one particular line and the Royal Society is strongly in favour of the development of renewables.

But the issue is how realistic is it?

One of the key technological issues with renewables is the variability of supply.

It's not just in the short timescale when you get big gusts of winds and you have to smooth that out.

It's at a time when we most need electricity, like the kind of day we had in Loughborough today, when it is beautiful, cold and clear, when there is not a breath of wind and we're not going to get much sunshine which could be taken up.

And therefore we couldn't generate renewables when we need them.

In the longer term, it may well be there are alternative sources of power to nuclear.

One could look to fusion which has the potential to be cleaner.

Stephen Tindale, executive director of Greenpeace in the UK

Nuclear power is dirty in a different way to carbon.

It doesn't produce carbon dioxide but it does produce routinely radioactive emissions for which there are no safe levels, according to the World Health Organisation.

It also produces nuclear waste, which has to be actively managed for 200,000 years.

No responsible government could agree to produce more nuclear waste at a time when we have no solution for dealing with it.

We have to get our energy from somewhere, although we could do with taking efficiency more seriously.

We think 10% (renewable energy) would be easily achievable if the government pulled its finger out and really started supporting it Stephen Tindale Greenpeace

The point about the 10% target (the fraction of UK energy to be renewable by 2010) is that it is not theoretically ambitious.

There's plenty of renewable source out there.

It becomes ambitious if the government fails to make the investment in terms of public subsidy and fails to support renewables through planning guidance.

We think 10% would be easily achievable if the government pulled its finger out and really started supporting it, and beyond that we could go much further.

The problem with what the Royal Society seems to be suggesting - quite apart from the environmental impact of nuclear power - is that they seem to be saying 'Because there are problems with renewables, let's fall back on the nuclear option.'

The idea that building new nuclear power stations wouldn't require large amounts of public subsidy and wouldn't require a massive amount of tinkering with the planning system is a bit fanciful.

Intermittence (variability of supply) is only a short-term problem because there are many technologies, particularly the development of hydrogen, which will overcome the problem.

When the wind blows, we can use it to produce hydrogen cleanly from water.

And when the wind isn't blowing, we can use that hydrogen in the exact same way we currently use natural gas.

So as most technologists and energy experts will tell you, this issue of intermittence is only a passing phase

If we put the investment into it, we will get a system where we have an everlasting, clean energy supply without the dangers of terrorism and proliferation that come from supporting nuclear power.