Goran Persson, Sweden's prime minister, has raised eyebrows both at home and abroad for announcing in September that Sweden should be the first country to become independent of oil.
He reiterated on Wednesday that the goal can be reached.
"We will not be rid of oil by 2020. However, we will not be dependent on oil in any sector, in the sense that there will not be alternatives," he said.
If his governing Social Democrats win re-election in September, Persson pledged to make the environmental plan centre-stage in his policies.
"I think we are on the verge of a radical shift in our habits," he said.
A cornerstone of the plan will be to increase energy efficiency by at least 20%, through development of new technologies, he said.
But the toughest challenge will be to cut the amount of oil used by the country's four million vehicles by between 40% to 50%.
At present, only about 1% of cars run on alternative fuels.
Persson: Transport would prove
the toughest area to take on
Sweden's plan also calls for cutting industrial use of oil by 25% to 40%, in part through tax breaks for using alternative fuels.
The heating of houses and apartments, meanwhile, should be completely free of fossil fuels by 2020 - a goal Sweden is already close to meeting.
Most Swedish counties use district heating that distributes steam heat to apartments, often produced by burning garbage or wood.
Only 8% of Swedish houses are heated by oil, and as of January 1, those households get tax rebates if they switch to renewable sources.
The proposals were worked out by a commission appointed by Persson last year, which was chaired by the premier and included industry experts, university professors and business leaders.
"The toughest sector to take on will be transportation," Persson stressed.
"It is a matter of survival, that we eventually have something else to pour in the tank other than increasingly expensive gasoline"
Sweden's Prime Minister
The harsh Swedish winters and limited use of diesel engines mean Swedish vehicles use 20% more fuel than the EU average.
But with car makers Saab and Volvo providing thousands of jobs in Sweden, it is essential for the country to be a leader in developing alternative fuels, Persson said.
"It is a matter of survival, that we eventually have something else to pour in the tank other than increasingly expensive gasoline."
Sweden is already an EU leader in using alternative fuels, and 26% of the energy consumed in Sweden in 2003 came from renewable sources - more than four times as much as the European Union average of 6%, according to EU statistics.
About one-third of Sweden's energy is nuclear power. The rest comes mainly from coal and natural gas.
Commission member Stefan Edman, an environmental adviser to the government, said funding development of new technologies - which would also help the Swedish export industry - was key.
He said: "We are already a leading country for developing new technology in this area.
"We will never come near our goals if we do not increase efficiency."