I am today launching the Eco-towns Prospectus, which sets out the Government's vision for new towns of five to 20,000 homes which will be exemplar “green” developments, with the aim of achieving zero carbon across the whole development. Community and large scale combined heat and power could play an important role in meeting this objective and we are looking to each project to act as an exemplar for particular aspects of low and zero carbon technology. Alongside this and other sustainability objectives, we intend that eco-towns should play a key role in easing the affordability crisis by ensuring that between 30 and 50 per cent. of their new housing is affordable as well as meeting our other essential criteria on high quality design, good provision for jobs, sustainable travel, services and community development. The launch of the prospectus today will be accompanied by an invitation for local authorities and other stakeholders to respond with their views on potential sites.