A detailed plan to slash London's carbon emissions by 60% within 20 years and place the city at the forefront of the battle against climate change will be announced by Ken Livingstone.
The mayor will appeal to Londoners to stop using energy wastefully and will urge businesses to embrace green technology to heat and light offices and workplaces.
Mr Livingstone wants a quarter of London's electricity supply to be shifted from the national grid to local combined heat-and-power systems by 2025. The city will offer "green gurus" to help families make their lifestyles more environmentally friendly, and will subsidise supplies of cavity wall and loft insulation.
The move is the most far-reaching attempted by a big city in the UK, but dozens of others are also planning action to cut emissions. Nearly 200 local authorities have a signed a pledge to take action, known as the Nottingham Declaration, and other cities, such as Birmingham, have set targets to reduce greenhouse gases.
Officials say the "vast majority" of the measures announced today will save money, mainly in reduced fuel and energy bills. They estimate that half the required carbon savings can be made through simple changes in behaviour.
In his foreword to the published details of the plan, Mr Livingstone says: "All of us have a responsibility, actions taken at an individual level can have consequences that are unaccceptable for society as a whole. Buying a gas-guzzling 4x4 vehicle is an 'individual choice' but it creates carbon emisssions that contribute to global warming and harm everyone. It should be no more socially acceptable than to claim the right to dump rubbish in the street."
Today's plan calls for London's annual carbon dioxide emissions to shrink from 44m tonnes last year to 18m tonnes by 2025 - an average reduction of 4% each year. But these figures do not include emissions from aviation, which the mayor's office says it has no powers to constrain.
The expected increase in flights into Heathrow and City airports will see London's aviation emissions rise from 22m tonnes of carbon dioxide last year to 35m tonnes in 2025. That means, even if today's reductions across the domestic, commercial and transport sectors are achieved, London's overall emissions would only fall by 20%.
The 60% target also relies heavily on ministers introducing regulations that place a nationwide price on the carbon pollution caused by fossil fuel use. Mr Livingstone has drawn up plans for such a scheme in London, which would charge the drivers of the most polluting cars £25 to enter the congestion zone. Similar moves across other sectors must be an "absolute priority" for ministers, the mayor's office said.
Most of the measures announced today are aimed at increasing the take-up of existing steps to reduce emissions, through better marketing and awareness-raising.
The package, for which the mayor's office will set aside £47m on next year's budget, is an attempt by Mr Livingstone to place the environment and climate change at the heart of his political programme. His team claim the package is the most comprehensive to be introduced by any comparable city government. "It is the defining issue," one aide said.
Privately, Mr Livingstone's team criticises the Department for Environment and the environment secretary, David Miliband, for taking little practical action to curb carbon emissions.
· Up to 50% subsidies on insulation - free for homes on benefits - to target the 1.4m houses without proper insulation
· A "concierge service" costing £50 to £200 including an audit of a household and full management of the conversion to a greener lifestyle
· Green homes scheme to build on work of groups like the Energy Saving Trust
· Promotion of projects to encourage energy efficiency and minimise waste; recognition of firms doing the most
· "Green consultants" to encourage cycling and use of public transport
· Promotion of fuel-efficient cars
· Encouragement of combined heat and power schemes for schools, hospitals and housing developments. London wants to generate a quarter of its electricity this way by 2025