Under the proposals, known as Domestic Tradable Quotas (DTQs), every individual would be issued a "carbon card," from which points would be deducted every time the cardholder purchased fossil fuel, for example, by filling up a car or taking a flight.

Over time, the number of points allotted to each card would decline. High-energy users would be able to purchase points from low-energy users, with the end result being a trading market in carbon similar to the one already in place in the U.K. for industrial users.

A report set to be released this week by the Sustainable Development Commission, which advises Prime Minister Tony Blair on environmental issues, will recommend that by 2007, the British government should seriously consider introducing DTQs.

The report, a draft copy of which was obtained by Cybercast News Service, calls for more research into how the proposals would work in practice.

British Environment Minister Elliott Morley said in a telephone interview that the DTQ plan, also called personal carbon allowances, is one of several being considered by the government.

"Personal carbon allowances are a very attractive intellectual idea," he said. "The implementation would potentially be very expensive, but that shouldn't stop us from looking at the arguments," he said.

Morley said the government was also considering a straightforward carbon tax, and acknowledged that the complexity of a centrally run system could be a major barrier.

"There is a big job involved in explaining the idea of carbon allowances to the public (but) we shouldn't rule any idea out just on this basis," he said.

One of Britain's leading scientists looking into the proposals characterized DTQs as a form of rationing and said the project would start from a point of strict equality in the allocation of "carbon points," despite wide current disparities in individual energy usage.

"Every individual, whether you're the Queen or someone living in a poor neighborhood, will get the same carbon allocation," said Kevin Anderson of the Tyndall Center at the University of Manchester.

A bill to establish DTQs and a trading system was introduced in the last parliamentary session by MP Colin Challen, a member of Blair's Labor Party. Challen's legislation was introduced as a private members bill, where debate is limited to ten minutes, and it stood virtually no chance of passing.

Challen said that some sort of compulsory energy program would be necessary to meet Blair's environmental promises. Under the Kyoto accord, which the U.S. has backed out of, the U.K. will need to reduce its emissions by 12.5 percent by 2012.

Washington withdrew from the Kyoto Protocol in 2001. President George W. Bush said limits on greenhouse gas emissions would be too expensive to implement, harming the U.S. economy -- with adverse effects on American workers.

President Bush also argued that the agreement did require developing countries to reduce their greenhouse gas emissions, even though some of those countries -- such as China and India -- are among the world's heaviest polluters.

Some scientists question whether global warming is taking place to begin with -- and whether the Kyoto Protocol is an effective solution.

The Blair government, however, has unilaterally pledged to reduce U.K. carbon emissions by 60 percent by 2050. Scientists say more research is needed to understand how DTQs and other proposals designed to meet such goals would affect the British economy.

"We have to get far more personal in the ways we tackle carbon emissions," Challen said in a phone interview. "A voluntary approach will only get through to about 20 percent of the population."

Challen said his proposals have support among senior government officials in the U.K.'s Department for the Environment, Food and Rural Affairs, but said that some ministers were "understandably wary" of a mandatory plan with potentially sweeping economic consequences.

Researchers also have suggested that the plan could be linked to the Blair administration's proposed mandatory ID card, a controversial bill that is scheduled to be reconsidered in Parliament later this month.

A proposal to issue every U.K. resident with a card containing biometric information such as fingerprints and an iris scan was opposed by the Conservative and Liberal Democrat parties in the last legislative term, and the bill failed after time ran out.

Anti-card campaigners have expressed worries about the possibility that the vast majority of U.K. energy transactions would be logged in a central database.

"There's clearly many other ways such a (carbon trading) scheme could be offered without adding the massive bureaucracy of an ID card system," said Michael Parker, spokesman for the NO2ID group.

However, the plan's proponents suggest that the rationing system could be implemented within the decade.

"I'm not a betting man, but I think this could realistically be up and running within four to ten years," Anderson said.