The "big conversation", announced by Mr Blair at this year's Labour Party conference, is billed as a "grown-up discussion" between politicians and the public on key strategic challenges facing the UK.
The initiative, launched in late November, is intended to inform Labour's programme for the next general election - although critics rushed to dismiss it as a public relations exercise. It will be taken forward by postal and web-based surveys, subject-focused meetings and e-mail dialogues with Ministers.
The exercise is seeking answers to several questions in the environmental field - although many are highly general in nature:
The question falls some way short of putting the case for variable charging for waste collection, as advocated a year ago in the Strategy Unit's waste review (ENDS Report 335, pp 21-26 ). Indeed, Ministers have already stressed their preference for incentives and discounts for people who change their behaviour (ENDS Report 346, pp 36-37 ).
Labour asks if the option to build new nuclear power stations should be kept open "if in later years it looks as though it is impossible to meet our carbon targets" without them. Superficially, the question is an odd one - the recent energy White Paper went to some lengths to avoid ruling out new nuclear build (ENDS Report 338, pp 26-32 ). However, revived concerns on security of energy supplies have given new life to the nuclear lobby.
Labour also asks whether "planning restrictions that have been used to block windfarms and other renewables [should] be reduced and the economic benefits they offer to rural communities increased."
Other open-ended questions cover "the best ways to meet our own ambitious national targets", and the ways in which the Government can best support low-carbon technologies.
Labour also asks what more could be done to encourage the development of "environmentally cleaner" cars, buses and lorries, and whether the Government has got the right balance in provision and funding for differing transport modes. Aviation and its soaring environmental impacts do not warrant a mention (see pp 42-43 ).
More generally, Labour calls for a decoupling of economic growth from negative environmental impacts - the only reference to sustainable consumption or resource productivity. It asks whether the "polluter pays" principle should be extended, and how environmental goals can be achieved in ways that secure economic benefits.
On waste, the LibDems "aim to achieve recycling of 60% of household waste within 10 years" - much higher than anything being contemplated by the Government - and to set a "zero waste" target for all municipal waste in England by 2020. The landfill tax would be reformed into a broader waste tax "to remove the incentives for incineration and other unsustainable waste disposal options".
The climate change levy is condemned as "overcomplicated and bureaucratic" - and would be replaced by a carbon tax payable by all energy users not covered by the EU emissions trading scheme. The tax level would probably be increased above the levy rates, depending on the advice of a proposed Green Tax Commission.
More ambitious targets would be set for renewables, with a firm target to meet 20% of electricity supplies in 2020, underpinned by extension of the renewables obligation, rising to 50% by 2050. Nuclear power stations would be allowed to run to the end of their safe operating lives, but Sellafield's reprocessing and MOX plants would be wound up "as soon as it is practical to do so".
The LibDems promise to increase the number of Environment Agency inspectors "to support full implementation of the pollution control regime". This would be reinforced by higher penalties for polluters and legislation on corporate environmental liability. An Environmental Responsibility Act would set reporting requirements and environmental standards for businesses and government, backed by environmental audits for public bodies.
On transport, the LibDems promise less road building, more incentives for cleaner vehicles and stronger targets for local authorities to reduce traffic - including through congestion charging schemes and parking taxes. However, they rule out increasing petrol taxes further above inflation.
Other measures are aimed at greening Government, with a "Green Budget" assessment of every budget, a new Department covering environment, energy and transport, and legislation on access to environmental information.