British PM wants CO2 targets to be 80% by 2050

It will allow the Committee to make its recommendation while the Climate Change Bill is still before Parliament and in time for the target figure to be raised significantly.

The move was immediately welcomed by environmental groups who have been pressing for much bigger cuts in emissions.

Mr Brown told the Labour Party conference in Manchester that a rising global population was producing a greater demand for energy.

"And I am asking the climate change committee to report by October on the case for, by 2050 not a 60 per cent reduction in our carbon emissions, but an 80 per cent cut - and I want British companies and British workers to seize the opportunity and lead the world in the transformation to a low carbon economy and I believe that we can create in modern green manufacturing and service 1m new jobs."

Nearly two-thirds of people told a poll by Opinium they thought recent government measures to boost energy conservation needed to go much further, and half said they were doing their bit by installing insulation or turning down the thermostat.

However more than seven out of 10 of the nearly 2,000 people questioned said they were unwilling to pay higher taxes to combat environmental issues, and a similar number believed the green agenda had been "hijacked" to increase taxes.

The timing of the survey last week could also have had an impact on willingness to pay higher prices, coming as daily headlines warned about recession, unemployment, rising prices and a collapse in the housing market.

Mark Hodson, Opinium's head of research, said the public had lost faith in both politicians and the energy companies that they blame for huge price hikes in recent months.